Cita APA (7th ed.)

Turtledove, H. (2002). Counting up, counting down (first.). Ballantine books.

Cita Chicago (17th ed.)

Turtledove, Harry. Counting Up, Counting Down. first. New York: Ballantine books, 2002.

Cita MLA (9th ed.)

Turtledove, Harry. Counting Up, Counting Down. first. Ballantine books, 2002.