Coppack, T., Tindemans, I., Czisch, M., Van der Linden, A., Berthold, P., & Pulido, F. (2008). Can long-distance migratory birds adjust to the advancement of spring by shortening migration distance? The response of the pied flycatcher to latitudinal photoperiodic variation. Global Change Biology, 14(11), 2516-2522. doi:10.1111/j.1365-2486.2008.01668.x.