Παραπομπή APA

Appell, J. (2004). Nonlinear spectral theory. Walter de Gruyter.

Παραπομπή Chicago Style

Appell, Jurgen. Nonlinear Spectral Theory. New York: Walter de Gruyter, 2004.

Παραπομπή MLA

Appell, Jurgen. Nonlinear Spectral Theory. Walter de Gruyter, 2004.