อ้างอิง ของ ตุ่นปากเป็ด

  1. ↑ Strahan, Ronald; Van Dyck, Steve (April 2006). Mammals of Australia (3rd ed.). New Holland. ISBN 978-1-877069-25-3.
  2. ↑ Fleay, David H. (1980). Paradoxical Platypus: Hobnobbing with Duckbills. Jacaranda Press. ISBN 0-7016-1364-5.
  3. ↑ Grant, Tom (1995). The platypus: a unique mammal. Sydney: University of New South Wales Press. ISBN 0-86840-143-9.
  4. ↑ Griffiths, Mervyn (1978). The Biology of the Monotremes. Academic Press. ISBN 0-12-303850-2.
  5. ↑ Hutch, Michael; McDade, Melissa C., ed. (2004). Grzimek's Animal Life Encyclopedia 12. Gale.