ISBN 3112735986 books & textbook
Introduction to the Spectral Theory of Operators in Spaces with an Indefinite Metric (Mathematical Research, 9)
Iohvidov, I. S. Krein, M. G. Langer, H.
De Gruyter /1982-12-31 Hardcover / 120 Pages
isbn-10: 3112735986 / isbn-13: 9783112735985