- [Wiki]
http://en.wikipedia.org/wiki/Zonotrichia_capensis.
- [avibase]
https://avibase.bsc-eoc.org/species.jsp?lang=EN&avibaseid=3647E146F88AE943&sec=lifehistory.
- [AnAge]
https://genomics.senescence.info/species/entry.php?species=Pooecetes_gramineus.
- [DawsEvan1960]
Dawson, W. R. and Evans, F. C. (1960).
Relation of growth and development to temperature regulation in
nestling vesper sparrows.
The Condor, 62(5):329--340.
- [Kooy2010]
Kooijman, S. (2010).
Dynamic Energy Budget theory for metabolic organisation.
Cambridge Univ. Press, Cambridge.
- [PrinPres1991]
Prinzinger, R., A.Preßmar, and Schleucher, E. (1991).
Body temperature in birds.
Comp. Biochem. Physiol., 99A(4):499--506. doi:10.1016/0300-9629(91)90122-S.