Baidu

CLOCKSS

CNPIEC

Chemical Abstracts Service (CAS)

Dimensions

EBSCO

EMBASE

Gale

Google Scholar

Japanese Science and Technology Agency (JST)

Naver

Norwegian Register for Scientific Journals and Series

OCLC WorldCat Discovery Service

Portico

ProQuest

Reaxys

SCImago

SCOPUS

Science Citation Index Expanded (SCIE)

Semantic Scholar

TD Net Discovery Service

Wanfang

National Institute of Health (NIH)