Bibliography:Sturm-Liouville theory


 * R. V. Churchill, "Fourier Series and Boundary Value Problems", pp. 70-72, (1963) McGraw-Hill, ISBN 0-07-010841-2.
 * P. Hartman, Ordinary Differential Equations, SIAM, Philadelphia, 2002 (2nd edition). ISBN 978-0-898715-10-1
 * A. D. Polyanin and V. F. Zaitsev, Handbook of Exact Solutions for Ordinary Differential Equations, Chapman & Hall/CRC Press, Boca Raton, 2003 (2nd edition). ISBN 1-58488-297-2
 * G. Teschl, Ordinary Differential Equations and Dynamical Systems, http://www.mat.univie.ac.at/~gerald/ftp/book-ode/ (Chapter 5)
 * G. Teschl, Mathematical Methods in Quantum Mechanics and Applications to Schrödinger Operators, http://www.mat.univie.ac.at/~gerald/ftp/book-schroe/ (see Chapter 9 for singular S-L operators and connections with quantum mechanics)
 * A. Zettl, Sturm–Liouville Theory, American Mathematical Society, 2005. ISBN 0-8218-3905-5.