Local library systems : Essen symposium, 24 September-27 September 1984 : festschrift in honour of Frederick G. Kilgour to his 70th birthday - Helal, A. H. (Ahmed H.); Kilgour, Frederick G.; Weiss, J. W. (Joachim W.) (Gesamthochschulbibliothek Essen, 1984)