@book{26328,
	author = {Bers, Lipman and others and John, Fritz ; jt. auth.},
	title = {Partial differential equations},
	publisher = {American Mathematical Society},
	year = {1964},
	series = {Lectures in applied Mathematics },
	address = {Providence},
	note = {"Proceedings of the Summer Seminar, Boulder, Colorado, 1957"}
}