APA-referens

Titchmarsh, E. C. (1962). Eigenfunction expansions associated with second-order differential equations (2d ed.). Clarendon Press.

Chicago-stil citat

Titchmarsh, E. C. Eigenfunction Expansions Associated with Second-order Differential Equations. 2d ed. Oxford: Clarendon Press, 1962.

MLA-referens

Titchmarsh, E. C. Eigenfunction Expansions Associated with Second-order Differential Equations. 2d ed. Clarendon Press, 1962.