Krauskopf, K. B., & Beiser, A. (1991). The physical universe (6th ed.). McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Krauskopf, Konrad Bates, agus Arthur Beiser. The Physical Universe. 6th ed. New York: McGraw-Hill, 1991.
Lua MLA (9ú heag.)Krauskopf, Konrad Bates, agus Arthur Beiser. The Physical Universe. 6th ed. McGraw-Hill, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.