Template:MSW3 Monotremata
Appearance
Groves, C. P. (2005). "Order Monotremata". In Wilson, D. E.; Reeder, D. M (eds.). Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 1–2. ISBN 978-0-8018-8221-0. OCLC 62265494.CS1 maint: ref=harv (link)