Roman L. Tatusov Darren A. Natale Igor V. Garkavtsev Tatiana A. Tatusova Uma T. Shankavaram Bachoti S. Rao Boris Kiryutin Michael Y. Galperin Natalie D. Fedorova Eugene V. Koonin The COG database: new developments in phylogenetic classification of proteins from complete genomes. 22-28 2001 29 Nucleic Acids Research 1 db/journals/nar/nar29.html#TatusovNGTSRKGFK01 http://dx.doi.org/10.1093/nar/29.1.22