@book{93064,
	author = {Guenther, Ronald B., and Lee, John W.,},
	title = {Sturm-Liouville problems :},
	publisher = {CRC Press, Taylor & Francis Group,},
	year = {[2019]},
	series = {Monographs and research notes in mathematics},
	address = {Boca Raton, FL :},
	url = {https://www.taylorfrancis.com/books/9780429437878}
}