Fraknoi, A., & Morrison, D. W. (2001). Voyages through the universe (2nd ed.). Harcourt College Publishers.
Chicago Stili AlıntıFraknoi, Andrew, ve David Wolff Morrison. Voyages Through the Universe. 2nd ed. Philadelphia: Harcourt College Publishers, 2001.
MLA AlıntıFraknoi, Andrew, ve David Wolff Morrison. Voyages Through the Universe. 2nd ed. Harcourt College Publishers, 2001.
Uyarı: Bu alıntı herzaman %100 doğru olmayabilir..