·       Baidu

·       CLOCKSS

·       CNPIEC

·       Chemical Abstracts Service (CAS)

·       Dimensions

·       EBSCO

·       Gale

·       Google Scholar

·       INIS Atomindex

·       Japanese Science and Technology Agency (JST)

·       Naver

·       OCLC WorldCat Discovery Service

·       Portico

·       ProQuest

·       SCImago

·       SCOPUS

·       Science Citation Index Expanded (SCIE)

·       Semantic Scholar

·       TD Net Discovery Service

·       UGC-CARE List (India)

·       Wanfang