Hapgood, C. H. (1970). The path of the pole (2nd ed.). Chilton.
Lua i Stíl Chicago (17ú heag.)Hapgood, Charles H. The Path of the Pole. 2nd ed. Philadelphia: Chilton, 1970.
Lua MLA (9ú heag.)Hapgood, Charles H. The Path of the Pole. 2nd ed. Chilton, 1970.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.