APA-referens (7:e uppl.)

Groot, B. d. (1961). Libido and semen characteristics of bull twins with special regard to genotypic and environmental variability. G. van Dijk.

Chicago-referens (17:e uppl.)

Groot, Bram de. Libido and Semen Characteristics of Bull Twins with Special Regard to Genotypic and Environmental Variability. Breukelen: G. van Dijk, 1961.

MLA-referens (8:e uppl.)

Groot, Bram de. Libido and Semen Characteristics of Bull Twins with Special Regard to Genotypic and Environmental Variability. G. van Dijk, 1961.