Cita APA

Sawyer, R. T., & Sawyer, R. T. (1972). North American freshwater leeches, exclusive of the piscicolidae, wtih a key to all especies. Urbana: University of Illinois Press.

Citación estilo Chicago

Sawyer, Roy T., y Roy T. Sawyer. North American Freshwater Leeches, Exclusive of the Piscicolidae, Wtih a Key to All Especies. Urbana: University of Illinois Press, 1972.

Cita MLA

Sawyer, Roy T., y Roy T. Sawyer. North American Freshwater Leeches, Exclusive of the Piscicolidae, Wtih a Key to All Especies. Urbana: University of Illinois Press, 1972.