APA (7th ed.) Citation

Steel. (2000). Target earth: The search for rogue asteroids. A Reader's Digest Book.

Chicago Style (17th ed.) Citation

Steel. Target Earth: The Search for Rogue Asteroids. London: A Reader's Digest Book, 2000.

MLA (8th ed.) Citation

Steel. Target Earth: The Search for Rogue Asteroids. A Reader's Digest Book, 2000.