found: Random House(monotreme: any animal of the Monotremata, the most primitive order of mammals)
found: Web. 3(monotreme: one of the Monotremata)
found: Mammal species of the world, via WWW, Mar. 11, 2000(Order Monotremata. Common name: Monotremes)
found: Walker's mammals of the world, via WWW, Mar. 11, 2000(Monotremata: Monotremes)
found: LC database, Mar. 11, 2000(ti: Marsupials and monotremes of Australia; Biology of the monotremes; Monotremes and marsupials; Australasian marsupials and monotremes; Handbook of New Guinea marsupials & monotremes; Catalogue of the Marsupialia and Monotremata in the collection of the British Museum (Natural History))
