Science Citation Index Expanded (SciSearch), Journal Citation Reports/Science Edition, SCOPUS, INSPEC, Astrophysics Data System (ADS), Chemical Abstracts Service (CAS), GEOBASE, Google Scholar, CSA, Academic OneFile, Chinese Science Citation Database, Current Contents/Physical, Chemical and Earth Sciences, Expanded Academic, GeoRef, OCLC, SCImago, Summon by ProQuest, Zoological Record