APA استشهاد

Terzian, Y., & Bilson, E. (1997). Carl Sagan's universe. Uty.Press.

استشهاد بنمط شيكاغو

Terzian, Yervant, و Elizabeth Bilson. Carl Sagan's Universe. Cambridge: Uty.Press, 1997.

MLA استشهاد

Terzian, Yervant, و Elizabeth Bilson. Carl Sagan's Universe. Uty.Press, 1997.