APA (7th ed.) Citation

Kopal, Z. (1971). Widening horizons: Man's quest to understand the structure of the universe. Taplinger.

Chicago Style (17th ed.) Citation

Kopal, Zdeněk. Widening Horizons: Man's Quest to Understand the Structure of the Universe. New York: Taplinger, 1971.

MLA (9th ed.) Citation

Kopal, Zdeněk. Widening Horizons: Man's Quest to Understand the Structure of the Universe. Taplinger, 1971.