Cita APA (7a ed.)

Shapp, M., & Shapp, C. (1961). Let's find out what's in the sky. Franklin Watts.

Cita Chicago Style (17a ed.)

Shapp, Martha, y C. Shapp. Let's Find Out What's in the Sky. New York: Franklin Watts, 1961.

Cita MLA (9a ed.)

Shapp, Martha, y C. Shapp. Let's Find Out What's in the Sky. Franklin Watts, 1961.