APA (7th ed.) Citation

Fretwell, L. (1956). Cosmic Rays at the North Pole. California Institute of Technology.

Chicago Style (17th ed.) Citation

Fretwell, Lyman. Cosmic Rays at the North Pole. California Institute of Technology, 1956.

MLA (8th ed.) Citation

Fretwell, Lyman. Cosmic Rays at the North Pole. California Institute of Technology, 1956.

Warning: These citations may not always be 100% accurate.