Titchmarsh, E. C. (1962). Eigenfunction expansions associated with second-order differential equations (2d ed.). Clarendon Press.
Cita Chicago (17th ed.)Titchmarsh, E. C. Eigenfunction Expansions Associated with Second-order Differential Equations. 2d ed. Oxford: Clarendon Press, 1962.
Cita MLA (8th ed.)Titchmarsh, E. C. Eigenfunction Expansions Associated with Second-order Differential Equations. 2d ed. Clarendon Press, 1962.
Atenció: Aquestes cites poden no estar 100% correctes.