APA (7th ed.) Citation

ASHFORD & COLLINS. (1991). Your spaceflight manual: How you could be a tourist in space within twenty years. Gresent Books.

Chicago Style (17th ed.) Citation

ASHFORD and COLLINS. Your Spaceflight Manual: How You Could Be a Tourist in Space Within Twenty Years. New York: Gresent Books, 1991.

MLA (8th ed.) Citation

ASHFORD and COLLINS. Your Spaceflight Manual: How You Could Be a Tourist in Space Within Twenty Years. Gresent Books, 1991.