Cita APA (7a ed.)

Wilkening, L. L. (1982). Comets. University of Arizona Press.

Cita Chicago Style (17a ed.)

Wilkening, Laurel L. Comets. Tucson: University of Arizona Press, 1982.

Cita MLA (9a ed.)

Wilkening, Laurel L. Comets. University of Arizona Press, 1982.