Judicial Commission of the International Committee on Systematics of Prokaryotes (2005). "The nomenclatural types of the orders Acholeplasmatales, Halanaerobiales, Halobacteriales, Methanobacteriales, Methanococcales, Methanomicrobiales, Planctomycetales, Prochlorales, Sulfolobales, Thermococcales, Thermoproteales and Verrucomicrobiales are the genera Acholeplasma, Halanaerobium, Halobacterium, Methanobacterium, Methanococcus, Methanomicrobium, Planctomyces, Prochloron, Sulfolobus, Thermococcus, Thermoproteus and Verrucomicrobium, respectively. Opinion 79". Int. J. Syst. Evol. Microbiol. 55 (Pt 1): 517–518. doi:10.1099/ijs.0.63548-0. PMID15653928.
Euzeby JP; Tindall BJ (2001). "Nomenclatural type of orders: corrections necessary according to Rules 15 and 21a of the Bacteriological Code (1990 Revision), and designation of appropriate nomenclatural types of classes and subclasses. Request for an Opinion". Int. J. Syst. Evol. Microbiol. 51 (Pt 2): 725–727. PMID11321122.
Boone, DR (2001). "Class I. Methanobacteria class. nov.". Dalam DR Boone and RW Castenholz, eds. (ed.). Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (Edisi 2nd). New York: Springer Verlag. hlm.169. ISBN978-0-387-98771-2.
Murray, RGE (1984). "The higher taxa, or, a place for everything...". Dalam NR Krieg and JG Holt, eds. (ed.). Bergey's Manual of Systematic Bacteriology, Volume 1 (Edisi 1st). Baltimore: The Williams & Wilkins Co. hlm.31–34.