1. Andresen, E., 1957. Blodtypeforskningen hos svinet, Raport Den Kgl. Veterinaer- og Landbohøjs koles afd. f. Fysiologi, Endakrinologi og Blodtypeforskning, 1, 21.
2. Andresen, E., 1963. A study of blood groups of the pig, Munksgaard, Copenhagen, pp. 30–32.
3. Hojný, J. and Hála, K., 1965. Blood group system O in pigs. Blood groups of animals, Edited by J. Matoušek, Publishing House of the Czechoslovak Academy of Sciences, Prague, pp. 163–168.
4. Hojný, J., Gavalier, M., Hradecký, J. and Linhart, J., 1966. New blood factors in pigs. Polymorphismes biochimiques des animaux. Xe Congrès européen sur les groupes sanguins et le polymorphisme biochimique des animaux, Paris, pp. 151–158.