APA (7th ed.) Citation

Gould, S., & Harper, R. (1984). Potential energy. [publisher not identified].

Chicago Style (17th ed.) Citation

Gould, Steve, and Rory Harper. Potential Energy. [Place of publication not identified]: [publisher not identified], 1984.

MLA (9th ed.) Citation

Gould, Steve, and Rory Harper. Potential Energy. [publisher not identified], 1984.