Sciencedirect http://www.sciencedirect.com

EBSCO http://www.daneshyar.org

American chemical society (ACS http://www.acs.org

American mathematical society (AMS) http://www.ams.org

Oxford university press(OUP) http://www.oxfordjournals.org/

Proquest http://proquest.umi.com/login

Scopus http://www.scopus.com/home.url

ISI http://apps.isiknowledge.com

Scirus http://www.scirus.com

Sage Publication http://online.sagepub.com