Database resources of the National Center for Biotechnology Information: 2002 update.
David L. WheelerDeanna M. ChurchAlex E. LashDetlef D. LeipeThomas L. MaddenJoan U. PontiusGregory D. SchulerLynn M. SchrimlTatiana A. TatusovaLukas WagnerBarbara A. RappPublished in: Nucleic Acids Res. (2002)