Steel, D. (1995). Rogue asteroids and doomsday comets: The search for the million megaton menace that threatens life on earth. Wiley.
Citazione stile Chigago Style (17a edizione)Steel, Duncan. Rogue Asteroids and Doomsday Comets: The Search for the Million Megaton Menace That Threatens Life on Earth. New York: Wiley, 1995.
Citatione MLA (9a ed.)Steel, Duncan. Rogue Asteroids and Doomsday Comets: The Search for the Million Megaton Menace That Threatens Life on Earth. Wiley, 1995.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.