Παραπομπή σε μορφή APA (7η εκδ.)

Helgason, S. (2000). Groups and geometric analysis: Integral geometry, invariant differential operators, and spherical functions. American Mathematical Society.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Helgason, Sigurdur. Groups and Geometric Analysis: Integral Geometry, Invariant Differential Operators, and Spherical Functions. Providence: American Mathematical Society, 2000.

Παραπομπή σε μορφή MLA (8th εκδ.)

Helgason, Sigurdur. Groups and Geometric Analysis: Integral Geometry, Invariant Differential Operators, and Spherical Functions. American Mathematical Society, 2000.