Пошукові системи
https://scholar.google.com.ua/ – Google Scholar
http://www.altavista.com –AltaVista
http://www.hotbot.com – HotBot
http://infoseek.go.com – Infoseek
http://www.opentext.com – OpenText
http://www.lycos.com – Lycos
http://excite.com – Excite
http://www.metacrawler.com - Metacrawler
https://core.ac.uk/ – Core
https://www.base-search.net/ - Base
https://www.scimagojr.com/ - Scimago
https://duckduckgo.com/html/ - DuckDuckGo
https://www.emis.de/projects/EULER/ - EULER search engine
https://www.search.com/ - metasearch search engine
https://www.science.gov/ - science.gov
https://www.crossref.org/ - crossref
https://access.clarivate.com/login?app=wos - Web of Science
https://www.scopus.com/ - Scopus
https://oasis.geneseo.edu/ - oasis
https://oersi.org/resources/ - oersi
https://ouci.dntb.gov.ua/ - Open Ukrainian Citation Index (OUCI)
https://www.scienceresearch.com/scienceresearch/desktop/en/search.html - scienceresearch.com
https://www.refseek.com/ - RefSeek
http://www.freefullpdf.com/#gsc.tab=0 - FreeFullLiDF
https://www.econbiz.de/ - EconBiz
https://worldwidescience.org/ - WorldWideScience.org
https://oaister.worldcat.org/ - OAIster