@book{19597,
	author = {Colloquium on Contributions to operator theory in spaces with an indefinite metric, Univ. of Vienna, Oct. 12-13, 1995 and Dijksma, A. and others ; eds.},
	title = {Contributions to operator theory in spaces with an indefinite metric; the Heinz Langer anniversary volume on his sixtieth birthday},
	publisher = {Birkhauser Verlag},
	year = {1998},
	address = {Basel}
}