Português: Coverage and Source Boundaries
Português localized draft: Supported databases, update cadence, evidence scope, and known gaps in LitSource.
Versão em português preenchida mecanicamente, mantendo a estrutura original em inglês; recomenda-se revisão humana.
Scope at a glance
LitSource is built for biomedical literature discovery and citation verification. We use different upstream sources for different parts of the product, so coverage is not identical across search, Verify, PDF access, and export.
Supported sources by workflow
| Workflow | Primary sources | What we use them for |
|---|---|---|
| Claim search / reverse literature search | LitSense sentence retrieval, with PubMed fallback | Find papers and passages related to a claim or draft sentence |
| Metadata enrichment | PubMed metadata, DOI records, citation signals | Title, journal, year, DOI, PMID, and related display fields |
| Citation verification (Verify) | Crossref, OpenAlex, Semantic Scholar | Check whether a citation appears real and whether core metadata matches |
| PDF / full-text access | Publisher links, PubMed Central (when available) | Open or download source PDFs when a public or linked file exists |
| PubMed query generation | LitSource query generator | Turn a research question into a PubMed-style query |
Update cadence
- Live or near-live API lookups: Verify and metadata checks rely on external APIs at request time, so freshness depends on the upstream source.
- Search retrieval: LitSense-backed retrieval is subject to the source index behind LitSense. PubMed fallback depends on current PubMed availability.
- PDF access: Availability depends on whether the publisher, repository, or PMC record currently exposes a file.
We do not guarantee that every source updates on the same schedule.
What can be searched today
- Biomedical claims, sentences, and short paragraphs in LitSource search
- PubMed-oriented research questions for query generation
- Reference lists for authenticity and metadata checks in Verify
- English biomedical literature most reliably
- Chinese input as a search prompt, where we map intent into English biomedical retrieval
Abstract vs full text
Coverage differs by source:
- Search results: often originate from indexed sentence or passage retrieval and may link out to PubMed or DOI pages.
- Abstract-level access: common when metadata or abstracts are available from PubMed or other upstream records.
- Full-text access: depends on whether a PMC article, publisher page, or another linked source exposes the full text or PDF.
- Verify: checks citation existence and metadata consistency; it is not a full-text fact-checking system for every reference.
What is not fully covered
- Comprehensive coverage of every publisher full text
- Closed-access articles without accessible metadata or file links
- Complete coverage of non-biomedical fields
- Comprehensive Chinese journal coverage such as CNKI or Wanfang
- A guarantee that every search result includes full-text evidence labels inline in the current UI
How to read evidence boundaries
Use the following practical rule:
- If LitSource shows a PubMed or DOI link, you should still open the source and confirm the claim against the original record.
- If a PDF is available, that reflects source availability, not a separate guarantee from LitSource.
- If Verify cannot match a citation, that may mean the reference is wrong, incomplete, local-language only, or simply missing from the upstream databases we query.
Known gaps and caveats
- Search and Verify use different upstream systems, so a paper found in one workflow may not resolve the same way in another.
- Citation verification is strongest for references with DOI and standard journal metadata.
- Local-language references and grey literature are more likely to be under-covered.
- Export availability depends on plan access, not on source coverage.
Questions
If you need a source audit for an institutional workflow, contact [email protected].