• [Wiki] http://en.wikipedia.org/wiki/Motacilla_citreola.
• [AnAge] http://genomics.senescence.info/species/entry.php?species=Anthus_spinoletta.
• [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.
• [Verb1988] Verbeek, N. A. M. (1988). Development of a stable body temperature and growth rates in nestlings of three ground nesting passerines in alpine tundra. J Ornithol, 129:449--456.