APA (7th ed.) Citation

Asimov, I. (1982). How we found out about black holes. Longman.

Chicago Style (17th ed.) Citation

Asimov, Isaac. How We Found Out About Black Holes. Harlow: Longman, 1982.

MLA (9th ed.) Citation

Asimov, Isaac. How We Found Out About Black Holes. Longman, 1982.

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