Citazione Stile APA (7a Edizione)

Friedrichs, K. O. (1961). Spectral theory of operators in Hilbert Space. New York University.

Citazione stile Chigago Style (17a edizione)

Friedrichs, K. O. Spectral Theory of Operators in Hilbert Space. Nueva York: New York University, 1961.

Citatione MLA (9a ed.)

Friedrichs, K. O. Spectral Theory of Operators in Hilbert Space. New York University, 1961.