Database resources of the National Center for Biotechnology.
David L. WheelerDeanna M. ChurchScott FederhenAlex E. LashThomas L. MaddenJoan U. PontiusGregory D. SchulerLynn M. SchrimlEdwin SequeiraTatiana A. TatusovaLukas WagnerPublished in: Nucleic Acids Res. (2003)