Παραπομπή APA

Gardner, M., & Schroeder, T. (1997). Puzzling questions about the solar system. Dover Publications.

Παραπομπή Chicago Style

Gardner, Martin, και Ted Schroeder. Puzzling Questions About the Solar System. Mineola, N.Y.: Dover Publications, 1997.

Παραπομπή MLA

Gardner, Martin, και Ted Schroeder. Puzzling Questions About the Solar System. Dover Publications, 1997.