APA (7e ed.) Bronvermelding

Pearl, R. (1927). The cost of biological books in 1927. s.n..

Chicago (17e ed.) Bronvermelding

Pearl, Raymond. The Cost of Biological Books in 1927. [Baltimore: s.n., 1927.

MLA (8e ed.) Bronvermelding

Pearl, Raymond. The Cost of Biological Books in 1927. s.n., 1927.