Garrity GM, Bell JA, Lilburn TG. Taxonomic Outline of the Procaryotes. Bergey's Manual of Systematic Bacteriology, Second Edition, Release 4.0. Springer-Verlag, New York, 2003.
not validly published
The type order of this class has alternatively been placed in the class Methanococci Boone 2002.Publication:
Garrity GM, Holt JG. The Road Map to the Manual. In: Boone DR, Castenholz RW, Garrity GM (eds), Bergey's Manual of Systematic Bacteriology, second edition, vol. 1 (The Archaea and the deeply branching and phototrophic Bacteria), Springer-Verlag, New York, 2001, p. 119-166.
Number of child taxa with a validly published and correct name: 3 Number of child taxa with a validly published name, including synonyms: 3 Total number of child taxa: 4