Wallraff, Hans Georg Verhaltensphysiologie, Seewiesen, Max Planck Institut für Ornithologie, Max Planck Society;
Wallraff, H. G., & Andreae, M. O. (2000). Spatial gradients in ratios of atmospheric trace gases: A study stimulated by experiments on bird navigation. Tellus, Series B - Chemical and Physical Meteorology, 52(4), 1138-1157. doi:10.1034/j.1600-0889.2000.00099.x.