03 · What You Need to Know
How to Build a Literature Search Without a Database You Expected to Use
First, Identify What You Actually Cannot Access
"I don't have access" can describe several different problems.
You may be unable to search the database at all. You may be able to search it but not retrieve the full text of the articles you find. Your institution may subscribe to the database through a different platform or library page. Remote access may require institutional authentication. Or you may simply have searched for the database through the open web rather than through your university library.
Database access
Whether you can search the bibliographic or citation database itself and use its records, indexing, filters, and other search functions.
Full-text access
Whether you can read or download a particular article or other document after discovering it.
These are separate problems. You can sometimes search a database without having access to every article it indexes, and you can sometimes obtain an article legally even though you cannot search the subscription database through which someone else discovered it.
Check Your University Library Before Assuming You Do Not Have Access
If you are affiliated with a university, begin with its library website rather than the database provider's public homepage.
Search the library's database directory or A-to-Z list. Check subject guides for your discipline. If you are off campus, sign in through the institution's remote-access system. Some subscriptions are authenticated through institutional credentials, proxy systems, or other access mechanisms that are not obvious when you visit a provider directly.
If the database still appears unavailable, ask a librarian.
This is not merely a troubleshooting step for beginners. Librarians and information specialists work directly with subscription systems, database platforms, link resolvers, subject resources, and literature-search methods. For systematic reviews in healthcare, current Cochrane guidance explicitly recommends involving an experienced medical or healthcare librarian or information specialist from the protocol stage.
Determine Why You Wanted That Particular Database
Before looking for a substitute, ask what the missing database was supposed to contribute.
Was it intended to provide broad multidisciplinary coverage? Was it the major subject database for your discipline? Did you need its controlled vocabulary? Citation searching? Conference proceedings? Historical coverage? Particular journals? Citation metrics?
The answer determines what counts as a reasonable alternative.
| What You Needed |
What to Look for in an Alternative |
| Broad scholarly discovery |
A multidisciplinary scholarly search resource with relevant disciplinary coverage |
| Field-specific literature |
A specialized database or repository serving that discipline |
| Controlled vocabulary |
A database with an appropriate thesaurus or subject-heading system |
| Citation searching |
A resource that exposes references and citing works |
| Open-access literature |
Repositories, open indexes, and open-access directories |
| Conference literature |
Field-specific conference indexes, digital libraries, or proceedings sources |
| Theses and dissertations |
Institutional repositories and dedicated thesis or dissertation databases |
| Government or policy evidence |
Government portals, organizational repositories, and targeted web searching |
Thinking in terms of function prevents a common mistake: replacing a missing database with whichever free search box happens to be easiest to reach.
Some Important Research Databases Are Already Free
Subscription databases are prominent in academic research, but subscription access is not synonymous with scholarly searching.
PubMed is freely available for biomedical and life-sciences literature. ERIC provides free searching for education research. Google Scholar is freely searchable across scholarly literature from many disciplines. Other freely accessible scholarly infrastructures can complement these established resources.
OpenAlex, for example, describes its works collection as covering scholarly documents including journal articles, conference papers, books, book chapters, datasets, dissertations, and preprints. Its data and search infrastructure can be useful for scholarly discovery and bibliometric work.
Semantic Scholar is another free multidisciplinary research tool for scientific literature. It provides paper discovery and citation and reference navigation, although its functions and coverage should not be treated as identical to Scopus or Web of Science.
For open-access journal literature, the Directory of Open Access Journals provides searchable journal and article records. CORE aggregates research from repositories and other sources with a strong emphasis on open-access research.
These resources expand your options considerably. They do not imply that every subscription database has a free one-for-one replacement.
Google Scholar Can Help, but Do Not Treat It as an Automatic Substitute
Google Scholar is particularly attractive when subscription databases are unavailable because it is free, multidisciplinary, and broad.
It can help you identify publications, locate related research, follow references, use Cited by to find later work, and sometimes locate accessible versions of papers.
Its usefulness does not eliminate its limitations. Search functionality, coverage transparency, bulk retrieval, and reproducibility differ from conventional bibliographic databases. If your project requires a systematic or highly comprehensive search, Google Scholar should not automatically be assumed to be sufficient on its own.
OpenAlex Can Provide Broad Open Scholarly Metadata
OpenAlex is an open scholarly information system covering hundreds of millions of works. Its records connect scholarly works with authors, sources, institutions, topics, funders, citations, and other entities.
For researchers without access to commercial citation databases, this makes OpenAlex potentially useful for literature discovery, citation-related exploration, bibliometric workflows, and checking scholarly metadata.
Its search and data model differ from Scopus and Web of Science, however. It should be evaluated on its own coverage and functionality rather than described as a free version of either commercial database.
Semantic Scholar Can Support Literature and Citation Discovery
Semantic Scholar is freely available and covers scientific literature across many fields. Its paper records expose references and citations and may provide links to available full-text versions.
That makes it useful for finding papers and following citation relationships when subscription citation databases are unavailable.
Again, similarity of function does not establish equivalence of coverage. If a method requires Scopus or Web of Science specifically, using Semantic Scholar changes the information source and should be reported accordingly.
DOAJ Is Useful When Open-Access Journal Literature Matters
The Directory of Open Access Journals is a freely accessible index focused specifically on open-access journals. It allows users to search journals and article records and describes its mission around making quality open-access content discoverable.
DOAJ is particularly useful when you want to identify legitimate open-access journals or search article metadata within its indexed content.
Its scope is intentionally different from multidisciplinary citation databases. It should therefore supplement rather than impersonate resources designed for other purposes.
CORE Can Help Locate Open Research
CORE aggregates research papers from repositories and other sources and describes itself as a large collection of open-access research papers.
Repository aggregation can be valuable when searching for accessible versions of research or literature distributed through institutional and subject repositories.
For literature reviews, however, an open-access aggregator should not automatically define the evidence base. Whether an article is freely available and whether it is relevant to the research question are separate matters.
Use Citation Searching to Work Outward From What You Can Find
If database coverage is constrained, citation searching becomes especially useful.
Start with several highly relevant publications. Examine their reference lists to find earlier research. Then use tools that provide citation links to identify later works that cite them.
Backward citation searching
Following a publication's reference list to earlier sources it cited.
Forward citation searching
Finding later publications that cite the publication you already know.
Citation searching can reveal relevant papers that use terminology you did not anticipate and therefore escaped your keyword searches.
It should not normally be presented as proof that you have reconstructed everything the unavailable database would have found. It is a complementary discovery method.
Use More Than One Alternative When the Missing Database Matters
If a database has distinctive coverage, expecting one free resource to replace it perfectly may be unrealistic.
A stronger strategy may combine a freely accessible subject database, a multidisciplinary scholarly search tool, citation searching, relevant repositories, and targeted searching for particular document types.
For example, a researcher without access to a multidisciplinary citation database might combine a specialized database relevant to the field with Google Scholar or OpenAlex for broader discovery and citation chasing. The exact combination should follow the question rather than a fixed recipe.
This reflects a broader principle about combining subject-specific and multidisciplinary search resources: complementary coverage can matter more than finding a single nominal replacement.
Test Alternative Resources With Known Relevant Papers
If you already know several papers that are clearly central to your topic, search for them in the alternative resources you are considering.
Can the resource find them by title? Are their references or citing works available? Does it index the journals or conference proceedings in which important studies appear? Does it provide enough metadata to distinguish relevant records?
This is not a formal proof of comprehensive coverage. A database finding five papers you already know does not establish that it contains everything else you need. It is nevertheless a useful diagnostic check for obvious coverage problems.
For a more defensible assessment, examine how to determine whether a database actually covers your field.
Do Not Confuse Database Access With Article Access
Suppose you can find the citation but the publisher asks for payment. That is a full-text access problem rather than a search problem.
Check whether your library provides the article through another subscription. Look for legitimate repository copies, accepted manuscripts, or open-access versions. Search the title or DOI. Institutional and subject repositories can contain author manuscripts even when the publisher's version is paywalled.
Library document delivery or interlibrary loan may also provide material unavailable through your institution's direct subscriptions.
Watch Out
Do not restrict your literature review to papers you can immediately download for free unless free availability is itself a justified eligibility criterion. Ease of access is not a methodological measure of relevance or research quality.
For Systematic Reviews, Missing Database Access Can Be a Methodological Limitation
Formal evidence synthesis deserves greater caution.
Cochrane's current guidance emphasizes extensive searching to reduce reporting bias and states that database selection should be guided by the review topic. For Cochrane intervention reviews specifically, CENTRAL and MEDLINE should be searched, together with Embase when access is available to the review team, as well as relevant specialized registers where applicable.
Other systematic review traditions and disciplines have their own expectations. The important principle is that inability to access an important database should be considered during search design rather than discovered after the review is written.
If the unavailable database is likely to contain unique eligible studies, use reasonable alternatives and report the limitation. Transparency is more defensible than implying that your search had coverage you could not actually provide.
A Database Used in Another Review Is Not Automatically Required for Yours
You may notice that nearly every published review on your topic searched the same commercial database. That is useful evidence about disciplinary practice, but it does not by itself prove that your review is invalid without access to that resource.
Examine why those researchers used it. Was it because of unique disciplinary coverage? Citation searching? Conference indexing? Institutional availability? Habit?
If another accessible database provides substantial overlapping coverage, the methodological consequences may be limited. If the inaccessible database is the principal index for the field, the problem is more consequential.
The relevant question is what literature becomes less discoverable when the database is removed from your search strategy.
