Gaya APA

BIRDSAL, S, S. et al ([s.a). Garis Besar Geografi Amerika : Lanskap Regional Amerika Serikat . [s.l]: United States Department of State.

Gaya MLA

BIRDSAL, Stephen, S. et al. "Garis Besar Geografi Amerika : Lanskap Regional Amerika Serikat". [s.l]: United States Department of State, [s.a. Text.