Beekman, J., Koffijberg, K., Wahl, J., Kowallik, C., Hall, C., Devos, K.
, Clausen, P., Hornman, M., Laubek, B., Luigujõe, L., Wieloch, M., Boland, H., Švazas, S., Leif, N., Stipniece, A., Keller, V., Gaudard, C., Degen, A., Shimmings, P. ... Rees, E. C. (2019).
Long-term population trends and shifts in distribution of Bewick’s Swans Cygnus columbianus bewickii wintering in northwest Europe.
Wildfowl,
2019(Special Issue No. 5), 73-102.
https://wildfowl.wwt.org.uk/index.php/wildfowl/article/view/2706
Elmeros, M., Christensen, M., Fjederholt, E. T., Johansen, T. W., Dahl Møller, J. & Baagøe, H. J., (2019).
NOVANA-overvågning af flagermus 2019, Notat fra DCE - Nationalt Center for Miljø og Energi