Goymann, Wolfgang Abteilung Gahr, Seewiesen, Max Planck Institut für Ornithologie, Max Planck Society;
Goymann, W., Landys, M. M., & Wingfield, J. C. (2007). Distinguishing seasonal androgen responses from male-male androgen responsiveness - Revisiting the Challenge Hypothesis. Hormones and Behavior, 51(4), 463-476. doi:10.1016/j.yhbeh.2007.01.007.