Cita APA (7th ed.)

Birnbaum, A. M., & Birnbaum, S. (1990). Birnbaum's United States, 1991. Houghton Mifflin.

Cita Chicago (17th ed.)

Birnbaum, Alexandra Mayes, i Stephen Birnbaum. Birnbaum's United States, 1991. Boston: Houghton Mifflin, 1990.

Cita MLA (9th ed.)

Birnbaum, Alexandra Mayes, i Stephen Birnbaum. Birnbaum's United States, 1991. Houghton Mifflin, 1990.