1. The harbour porpoise Phocoena phocoena (L., 1758) in The Netherlands: stranding records and decline;Smeenk;Lutra,1987
2. The cetaceans Phocoena phocoena and Tursiops truncatus in the Marsdiep area (Dutch Waddensea) in the years 1931–1973;Verwey;Nederlands Instituut voor Onderzoek der Zee, Publikaties en Verslagen,1975
3. Analysis of cetacean sightings in the British Isles 1958–1985;Evans,1986
4. Historical review of cetaceans in British and Irish waters;Evans,1989
5. The harbour porpoise Phocoena phocoena in the southern North Sea, particularly the Dutch sector;Camphuysen;Lutra,1993