APA-referens (7:e uppl.)

Bergman, G. M., & Hausknecht, A. O. (1996). Cogroups and Co rings in categories of associative rings. American Mathematical Society.

Chicago-referens (17:e uppl.)

Bergman, George M., och Adam O. Hausknecht. Cogroups and Co Rings in Categories of Associative Rings. Providence: American Mathematical Society, 1996.

MLA-referens (9:e uppl.)

Bergman, George M., och Adam O. Hausknecht. Cogroups and Co Rings in Categories of Associative Rings. American Mathematical Society, 1996.