Härkönen, T., Brasseur, S., Teilmann, J., Vincent, C., Dietz, R., Abt, K. and Reijnders, P. 2007. Status of grey seals along mainland Europe from the Southwestern Baltic to France. NAMMCO Scientific Publications. 6, (Jan. 2007), 57–68. DOI:https://doi.org/10.7557/3.2721.