Huber R; Stetter KO (2001). "Order I. Methanopyrales ord. nov.". In DR Boone; RW Castenholz (eds.). Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nded.). New York: Springer Verlag. 169.o. ISBN978-0-387-98771-2.
Garrity GM; Holt JG (2001). "Class VII. Methanopyri class. nov.". In DR Boone; RW Castenholz (eds.). Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nded.). New York: Springer Verlag. 169.o. ISBN978-0-387-98771-2.