The COG database: an updated version includes eukaryotes. - Roman L. Tatusov; Natalie D. Fedorova; John D. Jackson; Aviva R. Jacobs; Boris Kiryutin; Eugene V. Koonin; Dmitri M. Krylov; Raja Mazumder; Sergei L. Mekhedov; Anastasia N. Nikolskaya; B. Sridhar Rao; Sergei Smirnov; et al. (BMC Bioinform., 2003)

MMDB: Entrez's 3D-structure database. - Jie Chen 039; John B. Anderson; Carol DeWeese-Scott; Natalie D. Fedorova; Lewis Y. Geer; Siqian He; David I. Hurwitz; John D. Jackson; Aviva R. Jacobs; Christopher J. Lanczycki; Cynthia A. Liebert; Chunlei Liu 002; et al. (Nucleic Acids Res., 2003)

CDD: a curated Entrez database of conserved domain alignments. - Aron Marchler-Bauer; John B. Anderson; Carol DeWeese-Scott; Natalie D. Fedorova; Lewis Y. Geer; Siqian He; David I. Hurwitz; John D. Jackson; Aviva R. Jacobs; Christopher J. Lanczycki; Cynthia A. Liebert; Chunlei Liu 002; et al. (Nucleic Acids Res., 2003)