Gaya APA

Birdsall, S, S., Florin,John, . ([s.a]). Garis Besar Geografi Amerika: Lanskap regional Amerika Serikat . [s.n]: United States Department of State.

Gaya MLA

Birdsall, Stephen, S.., Florin,John, . "Garis Besar Geografi Amerika: Lanskap regional Amerika Serikat". [s.n]: United States Department of State, [s.a]. Text.