APA (7th ed.) Citation

Evans, D. S. (1946). Frontiers of astronomy. Sigma.

Chicago Style (17th ed.) Citation

Evans, David S. Frontiers of Astronomy. [London]: Sigma, 1946.

MLA (9th ed.) Citation

Evans, David S. Frontiers of Astronomy. Sigma, 1946.

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