Citazione Stile APA (7a Edizione)

Olson, S. F. (1998). Open horizons (1st University of Minnesota ed.). University of Minnesota Press.

Citazione stile Chigago Style (17a edizione)

Olson, Sigurd F. Open Horizons. 1st University of Minnesota ed. Minneapolis: University of Minnesota Press, 1998.

Citatione MLA (9a ed.)

Olson, Sigurd F. Open Horizons. 1st University of Minnesota ed. University of Minnesota Press, 1998.