So sánh phương pháp

	Danh mục Tạp chí Truy cập Mở	PubMed và MEDLINE	Ulrichsweb Global Serials Directory
Lĩnh vực	Trắc lượng thư mục	Trắc lượng thư mục	Trắc lượng thư mục
Họ	Process / pipeline	Process / pipeline	Process / pipeline
Năm ra đời	2003	1966	1932
Người khởi xướng	DOAJ Community (Swedish library consortium, later expanded to international consortium)	National Library of Medicine (NLM), U.S. National Institutes of Health	Bowker (originally R.R. Bowker), now ProQuest LLC
Loại	Database	Database	Database
Công trình gốc	Directory of Open Access Journals. (2024). About DOAJ. Retrieved from https://doaj.org/	National Library of Medicine. (2024). PubMed: Home. Retrieved from https://pubmed.ncbi.nlm.nih.gov/	ProQuest. (2024). Ulrichsweb: Global Serials Directory. Retrieved from https://ulrichsweb.serialssolutions.com/
Tên gọi khác	DOAJ, Directory of Open Access	PubMed, MEDLINE, NLM, PubMed Central	Ulrichsweb, Ulrich's International Periodicals Directory, Ulrich's Directory
Liên quan	5	5	4
Tóm tắt	The Directory of Open Access Journals (DOAJ) is a community-maintained, freely accessible directory of high-quality, peer-reviewed open-access journals and articles established in 2003. DOAJ indexes over 20,000 open-access journals across all disciplines (sciences, social sciences, humanities, arts) from diverse geographic regions. The directory serves researchers, librarians, and administrators as the authoritative curated list of legitimate open-access journals—differentiating quality open-access publications from predatory journals that lack genuine peer review. DOAJ quality seal, awarded to journals meeting stricter governance and transparency criteria, enables identification of the highest-caliber open-access publications.	PubMed is a free, publicly accessible literature database maintained by the National Library of Medicine (NLM), a division of the U.S. National Institutes of Health. It provides access to biomedical and life sciences literature from MEDLINE (the curated subset of ~30 million indexed journal articles), life science journals, in-process articles, and preprints. MEDLINE, established in 1966, is the gold standard for biomedical literature indexing, using MeSH (Medical Subject Headings), a hierarchical controlled vocabulary of ~33,000 terms. PubMed is the primary discovery tool for clinicians, researchers, and healthcare professionals worldwide seeking evidence-based information.	Ulrichsweb is a comprehensive, subscription-based global serials directory cataloging over 300,000 print and electronic journals, magazines, newspapers, and other periodical publications. Developed by ProQuest (originally R.R. Bowker), Ulrichsweb has served librarians and researchers for over 90 years as the authoritative source for journal metadata, publication information, and peer-review verification. A unique feature is Ulrichsweb's verification program: editorial staff contact journals directly to confirm peer-review claims, marking journals as 'refereed' only after validation. This verification process distinguishes legitimate peer-reviewed journals from predatory publishers falsely claiming peer review.