APA (7e ed.) Bronvermelding

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

Chicago (17e ed.) Bronvermelding

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

MLA (9e ed.) Bronvermelding

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