APA (7th ed.) Citation

Verma, S. (2007). Why aren't they here?: The question of life on other worlds. Icon Books.

Chicago Style (17th ed.) Citation

Verma, Surendra. Why Aren't They Here?: The Question of Life on Other Worlds. Thriplow: Icon Books, 2007.

MLA (9th ed.) Citation

Verma, Surendra. Why Aren't They Here?: The Question of Life on Other Worlds. Icon Books, 2007.

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