Olson, S. F. (1998). Open horizons (1st University of Minnesota ed.). University of Minnesota Press.
Lua i Stíl Chicago (17ú heag.)Olson, Sigurd F. Open Horizons. 1st University of Minnesota ed. Minneapolis: University of Minnesota Press, 1998.
Lua MLA (9ú heag.)Olson, Sigurd F. Open Horizons. 1st University of Minnesota ed. University of Minnesota Press, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.