Helfer, R. (1998). Modoc: The true story of the greatest elephant that ever lived (1st HarperPerennial ed.). HarperPerennial.
Cita Chicago Style (17a ed.)Helfer, Ralph. Modoc: The True Story of the Greatest Elephant That Ever Lived. 1st HarperPerennial ed. New York: HarperPerennial, 1998.
Cita MLA (8a ed.)Helfer, Ralph. Modoc: The True Story of the Greatest Elephant That Ever Lived. 1st HarperPerennial ed. HarperPerennial, 1998.
Precaución: Estas citas no son 100% exactas.