@book{12598,
	author = {Jorgens, Konard and Weidmann, Joachim and Weidmann, Joachim ; jt. auth.},
	title = {Spectral properties of Hamiltonian operators},
	publisher = {Springer-Verlag},
	year = {1973},
	series = {Lecture notes in Mathematics},
	address = {Berlin}
}