Bibliometrix
Bibliometric analysis in R — reproducible science mapping, code-first.
Tier 3 ToolsFree
Research Database Directory
Every research database, reviewed.
Publish or Perish
Citation metrics on demand — pull an author or topic's impact in seconds.
Tier 3 ToolsFree
Scholarcy
Auto-summarize any paper into a structured flashcard.
Tier 3 ToolsFreemium
Scilit
A fast, free scholarly index — MDPI's comprehensive metadata search.
Tier 3 Open AccessFree
DOAB
The Directory of Open Access Books — DOAJ's counterpart for scholarly monographs.
Tier 3 Open AccessFree
LILACS
Latin American and Caribbean health literature — the regional index PubMed misses.
Tier 3 Open AccessFree
PubMed Central (PMC)
The free full-text archive behind PubMed — biomedical papers you can actually read.
Tier 2 Open AccessFree
Inciteful
Fast, free citation-network analysis — find the papers that connect your papers.
Tier 3 ToolsFree
Undermind
Deep, agentic literature search — thorough where keyword search is shallow.
Tier 3 ToolsFreemium
Covidence
The systematic-review workflow — screening, extraction, and team collaboration.
Tier 2 ToolsFreemium