Schwabl, Hubert Verhaltensphysiologie, Seewiesen, Max Planck Institut für Ornithologie, Max Planck Society;
Schwabl, H. (1992). Winter and breeding territorial behaviour and levels of reproductive hormones of migratory European Robins. Ornis Scandinavica, 23(3), 271-276. doi:10.2307/3676649.