Παραπομπή APA

Helen, Helen Mellanby, & Helen Mellanby. (1953). Animal life in freshwater (5.). London.

Παραπομπή Chicago Style

Helen, Helen Mellanby, και Helen Mellanby. Animal Life in Freshwater. 5. London, 1953.

Παραπομπή MLA

Helen, et al. Animal Life in Freshwater. 5. London, 1953.