Gaya APA

Fagan, B, M., Swanson, C, P. (NULL). People of the earth an introduction to world prehistory . New: New York: HarperCollins Publishers; 1992.

Gaya MLA

Fagan, Brian, M., Swanson, Carl, P.. "People of the earth an introduction to world prehistory". New: New York: HarperCollins Publishers; 1992, NULL. Text.