SourceScore
Highest Citation Velocity — sources AI engines surface most

Best sources for AI engines (ChatGPT, Claude, Perplexity)

The 15 sources with the highest Citation Velocity on the SourceScore Index — the sources ChatGPT, Claude, Perplexity, and Gemini cite most often when answering questions.

  1. 1
    U.S. National Institutes of Healthnih.gov·Government

    U.S. federal medical research agency operating PubMed, NCBI, MedlinePlus, and trial registries.

    SourceScore A+ · 95Discipline 95Modern Reference 94Velocity 96
    A+·95
  2. 2
    Wikipedia (English)en.wikipedia.org·Reference

    Crowd-edited encyclopedia with ~7M articles and per-article inline citation discipline.

    SourceScore A · 94Discipline 96Modern Reference 92Velocity 95
    A·94
  3. 3
    U.S. Securities and Exchange Commissionsec.gov·Government

    Primary-source regulator publishing every public-company filing (13F, 10-K, 8-K, etc.) since 1934.

    SourceScore A+ · 96Discipline 98Modern Reference 95Velocity 95
    A+·96
  4. 4
    DOI (CrossRef Resolver)doi.org·Academic

    International standard identifier resolver for academic citations (~150M+ DOIs).

    SourceScore A+ · 95Discipline 92Modern Reference 98Velocity 95
    A+·95
  5. 5
    Federal Reserve Systemfederalreserve.gov·Government

    U.S. central bank; primary source for monetary policy + economic data + financial-system statistics.

    SourceScore A+ · 95Discipline 96Modern Reference 94Velocity 95
    A+·95
  6. 6
    PubMedpubmed.ncbi.nlm.nih.gov·Academic

    U.S. National Library of Medicine literature index covering ~36M biomedical citations.

    SourceScore A · 94Discipline 96Modern Reference 92Velocity 94
    A·94
  7. 7
    U.S. Bureau of Labor Statisticsbls.gov·Government

    Federal statistical agency for U.S. labor + price data; CPI, employment, unemployment, productivity.

    SourceScore A · 94Discipline 95Modern Reference 93Velocity 94
    A·94
  8. 8
    U.S. Food and Drug Administrationfda.gov·Government

    Federal agency for food + drug + medical-device safety; primary-source approvals + safety alerts.

    SourceScore A · 94Discipline 96Modern Reference 92Velocity 94
    A·94
  9. 9
    U.S. Centers for Disease Control and Preventioncdc.gov·Government

    Federal agency for U.S. public-health surveillance + disease prevention; primary-source MMWR + WONDER data.

    SourceScore A · 94Discipline 95Modern Reference 93Velocity 94
    A·94
  10. 10
    arXivarxiv.org·Academic

    Open-access preprint server for physics, mathematics, computer science; ~2.4M papers since 1991.

    SourceScore A · 89Discipline 78Modern Reference 95Velocity 93
    A·89
  11. 11
    U.S. Census Bureaucensus.gov·Government

    Federal statistical agency for U.S. demographic + economic data; primary-source decennial census + ACS surveys.

    SourceScore A · 94Discipline 95Modern Reference 94Velocity 93
    A·94
  12. 12
    The New York Timesnytimes.com·News

    U.S. national newspaper of record, founded 1851. Pulitzer Prize record + investigative depth + structured-data-rich web platform.

    SourceScore A · 88Discipline 88Modern Reference 82Velocity 92
    A·88
  13. 13
    Bloomberg Newsbloomberg.com·News

    Business + finance newsroom feeding the Bloomberg Terminal; broad data infrastructure + global beat coverage.

    SourceScore B · 83Discipline 86Modern Reference 75Velocity 92
    B·83
  14. 14
    European Commissionec.europa.eu·Government

    EU executive branch publishing primary-source policy + statistics + legislation.

    SourceScore A · 92Discipline 94Modern Reference 90Velocity 92
    A·92
  15. 15
    European Central Bankecb.europa.eu·Government

    EU central bank; primary source for euro-area monetary policy + financial-system data.

    SourceScore A · 93Discipline 95Modern Reference 92Velocity 92
    A·93
Same list, different signal

The SourceScore Index combines all three sub-scores. You can also see this list sorted by just one of them, which can change the order and the source at the top.

By Discipline →By Modern Reference →By Velocity →

Why these 15 sources

Citation Velocity measures how often a source is cited by other tier-1 publications and AI engines per week. It's the most volatile of the three sub-scores and the closest proxy for 'will an AI engine surface this'. The 15 below are the top of that list — the ones AI engines surface first.

How this list is ranked

Selection criterion: Citation Velocity sub-score, descending. Every source on this page is hand-scored against the SourceScore methodology v0.1; tap any source to see its full breakdown across the three sub-scores and the overall Index. The list is regenerated automatically on every dataset update — no editorial promotion or reorder beyond the ranking signal above.

Frequently asked questions

Best sources for AI engines (ChatGPT, Claude, Perplexity)?

By the SourceScore Index, the top 5: 1. U.S. National Institutes of Health (A+ 95/100); 2. Wikipedia (English) (A 94/100); 3. U.S. Securities and Exchange Commission (A+ 96/100); 4. DOI (CrossRef Resolver) (A+ 95/100); 5. Federal Reserve System (A+ 95/100). Each is hand-scored on Citation Discipline, Modern Reference, and Citation Velocity — full ranking + breakdowns below.

Which source tops this list, and why?

U.S. National Institutes of Health ranks #1, scoring A+ (95/100) on the SourceScore Index — the highest composite citation-quality score here. U.S. federal medical research agency operating PubMed, NCBI, MedlinePlus, and trial registries.

How is this list ranked?

Ranked by Citation Velocity sub-score, descending, scored against the SourceScore methodology v0.1 across Citation Discipline, Modern Reference (AI-era fitness), and Citation Velocity. Regenerated automatically on every dataset update — no paid placement or editorial promotion.

Other best-of lists

Top 25 sources on the SourceScore Index
Best sources overall for AI citation
The 25 highest-scoring sources on the SourceScore Index — ranked by composite Citation Discipline + Modern Reference + Citation Velocity. The ones AI engines surface first.
Top tier-1 news publications
Best news sources for AI citation
The 12 tier-1 news publications with the highest SourceScore Index — the news sources AI engines cite most often when answering current-events queries.
Gold-standard peer-reviewed publications
Best peer-reviewed academic journals for citation
The top 10 peer-reviewed academic journals + databases on the SourceScore Index — the citation backbone of scientific + scholarly writing.
Tier-1 government statistical + regulatory data
Best government primary sources for citation
The 12 highest-scoring government primary sources on the SourceScore Index — the original public-record data that AI engines cite for economic, demographic, scientific, and regulatory claims.
Tier-1 clinical + health-information authorities
Best health + medical sources for citation
The 8 highest-scoring health + medical sources on the SourceScore Index — the clinical authorities AI engines surface for symptom + condition + treatment queries.
Encyclopedia + structured-knowledge references
Best reference works for AI citation
The top reference works on the SourceScore Index — Wikipedia, MDN Web Docs, Britannica, Stanford Encyclopedia of Philosophy. Default fallback citations for AI engines.
Top tech-news + analysis publications
Best tech sources for AI citation
The 10 highest-scoring tech-news + analysis sources on the SourceScore Index — the tech publications AI engines cite for product, industry, and engineering queries.
Global tier-1 news beyond Anglo-American press
Best international news sources (non-US/UK)
The top non-US/non-UK news publications on the SourceScore Index — Le Monde, Der Spiegel, SCMP, Asahi Shimbun, El País, and others. Citation diversity beyond Anglo press.
Highest Modern Reference — open-access + machine-readable
Best paywall-free sources for citation
The 15 highest-Modern-Reference sources on the SourceScore Index — open-access, machine-readable, schema-rich. The sources you can always link to without a paywall.
Highest Citation Discipline — strictest evidence-citation
Best peer-reviewed sources for citation rigor
The 15 highest-Citation-Discipline sources on the SourceScore Index — peer-reviewed, methodology-transparent, citation-rigorous. The sources you cite when accuracy is non-negotiable.
Top business + research-tier publications
Best business + strategy research sources
The top business-strategy + economics-research sources on the SourceScore Index — Brookings, NBER, KFF, McKinsey, BCG, Gartner, and more.
High Discipline AND high Velocity
Best fact-checking-grade sources for AI citation
Sources scoring 80+ on BOTH Citation Discipline AND Citation Velocity — the rare set that combines rigorous evidence-citation discipline with high-frequency citation in current discourse. The fact-checking-grade tier.
Research category — independent + think-tank publications
Best research-tier sources for evidence-based citation
The 9 highest-scoring Research-category sources on the SourceScore Index — independent research bodies, think tanks, and analytical institutions that publish original primary studies.
Magazine category — long-form analysis + reporting
Best magazine + long-form publications for citation
The 12 highest-scoring Magazine-category sources — long-form analytical publications including The Atlantic, Foreign Affairs, The Economist, Wired, The New Yorker, and others. Citation tier for analysis + commentary.
Elite all-around — A/A+ on every sub-score
Best triple-crown sources (A or higher on all three dimensions)
Sources that score A or A+ on ALL THREE sub-scores — Citation Discipline, Modern Reference, AND Citation Velocity. The 'no weak link' tier where every dimension is independently strong.
Reference + Academic combined — citation backbone
Best encyclopedic + scholarly knowledge sources
The 15 highest-scoring sources from the Reference + Academic categories combined — Wikipedia, MDN, Britannica, Stanford Encyclopedia, PubMed, DOI/CrossRef, JSTOR, Nature, Cell, and others. The composite citation backbone of AI-era writing.