Helm, Barbara Verhaltensphysiologie, Seewiesen, Max Planck Institut für Ornithologie, Max Planck Society;
Hedenström, A., Barta, Z., Helm, B., Houston, A. I., McNamara, J. M., & Jonzen, N. (2007). Migration speed and scheduling of annual events by migrating birds in relation to climate change. Climate Research, 35(1-2), 79-91. doi:10.3354/cr00715.