APA استشهاد

Helgason, S. (1962). Differential geometry and symmetric spaces. Academic Press.

استشهاد بنمط شيكاغو

Helgason, Sigurdur. Differential Geometry and Symmetric Spaces. New York: Academic Press, 1962.

MLA استشهاد

Helgason, Sigurdur. Differential Geometry and Symmetric Spaces. Academic Press, 1962.