1. Bloch, D.: Ynglebestanden af Knopsvane (Cygnus olor) i Danmark i 1966. (The breeding population of the mute swan (Cygnus olor) in Denmark in 1966). Danske Vildtundersøgelser 1971, hefte 16, 43–44.
2. Jensen, S.: 1972. To be published.
3. Karlog, O., I. Kraul & Sv. Dalgaard-Mikkelsen: Residues of polychlorinated biphenyls (PCB) and organochlorine insecticides in liver tissue from terrestrial Danish predatory birds. Acta vet. scand. 1971, 12, 310–312.
4. Odsjö, T. & M. Olsson: Ekologisk miljögiftforskning. (Ecological research on environmental poisons). Sveriges natur. Årsbok 1971, 93–94.