H.B. Tordoff; W.R. Dawson (1965). "The influence of daylength on reproductive timing in the red crossbill". The Condor. 67 (5): 416–22. doi:10.2307/1365634. JSTOR1365634.
T.P. Hahn (1995). "Integration of photoperiodic and food cues to time changes in reproductive physiology by an opportunistic breeder, the red crossbill, Loxia curvirostra (Aves: Carduelinae)". J. Exp. Zool. 272 (3): 213–26. doi:10.1002/jez.1402720306.
H.B. Tordoff; W.R. Dawson (1965). "The influence of daylength on reproductive timing in the red crossbill". The Condor. 67 (5): 416–22. doi:10.2307/1365634. JSTOR1365634.
Martin R, Johnson P. Bennett's Tree-kangaroo. In: R. Straham, ed., Mammals of Australia, Washington, DC: Smithsonian Institution Press, 1995, pp. 307-8, PMID16026787
Wayne NL, Rissman EF (1990). "Environmental regulation of reproduction in an opportunistic breeder: the musk shrew (Insectivora: Suncus murinus)". Prog. Clin. Biol. Res. 342: 668–72. PMID2381955.