APA-referens

Ingpen, R., & Wilkinson, P. (1993). Encyclopedia of Ideas that Changed the World: The Greatest Discoveries and Inventions of Human History. Dragons World.

Chicago-stil citat

Ingpen, Robert, och Philip Wilkinson. Encyclopedia of Ideas That Changed the World: The Greatest Discoveries and Inventions of Human History. Limpsfield: Dragons World, 1993.

MLA-referens

Ingpen, Robert, och Philip Wilkinson. Encyclopedia of Ideas That Changed the World: The Greatest Discoveries and Inventions of Human History. Dragons World, 1993.