arXiv
arXiv returns up to 100 matching research preprints or individual paper details, and newly announced subject papers in announcement order; announcement dates may differ from today, and replacements are excluded.
bioRxiv
Biology and medicine preprints from bioRxiv and medRxiv.
Crossref
Find scholarly works and format citations from their registered metadata.
Google Scholar
Google Scholar provides papers, citing papers, ready-made citations and researcher profiles with metrics and up to 20 top-cited papers; public access may be temporarily limited.
NASA
NASA provides astronomy pictures from June 16, 1995 onward, up to 100 media matches, inclusive UTC asteroid approaches, recent approximate natural events, and upcoming ISS sightings for listed cities.
NIH RePORTER
Public research funding and project records from the National Institutes of Health.
OpenAlex
OpenAlex is an open catalog of scholarly research and connections, offering ranked papers and institution research summaries with annual output, leading topics, and coauthors.
ORCID
Researcher identifiers and public research records.
PubChem
PubChem provides compound facts and structures, plus available hazard labels, first aid, flash points, and workplace exposure limits; some fields may be unavailable.
Semantic Scholar
Semantic Scholar returns paper and citation search, paper abstracts, summaries, authors and influence, plus author metrics and up to 10 top-cited papers; dates, summaries, PDFs and affiliation matches may be unavailable.
The Space Devs
The Space Devs provides worldwide rocket launch schedules and mission details; public development listings may lag, and some launch details may be missing.
Unpaywall
Find free-to-read scholarly papers and their legal copies.
USGS Earthquakes
USGS Earthquakes provides recent event details, nearby earthquake distances and local times, and significant worldwide events from the past day, week, or month; some impact, felt, and alert information may be unavailable.
USGS Water Data
Public USGS river gauge readings and monitoring locations.