Helm, Barbara Seewiesen, Max Planck Institut für Ornithologie, Max Planck Society;
Helm, B., & Visser, M. E. (2010). Heritable circadian period length in a wild bird population. Proceedings of the Royal Society B: Biological Sciences, 277(1698), 3335-3342. doi:10.1098/rspb.2010.0871.