Gaya APA

Birdsall, S, S., Florin, J. (1992). Garis besar geografi amerika (Cet. 1). United States: united states department of state.

Gaya MLA

Birdsall, Stephen, S.., Florin, John. "Garis besar geografi amerika". Cet. 1 United States: united states department of state, 1992. Text.