found: Opitz, O. Operations Research Verfahren ... 1975.
found: His Scharfe und unscharfe Klassifikation qualitativer Daten, 1981:t.p. (Martin Schader, Hochschule der Bundeswehr, Hamburg) p. 2 (Prof. Dr.)
found: Classification Society. Meeting (9th : University of Karlsruhe : 1985). Classification as a tool of research, 1986:CIP t.p. (M. Schader, Institut für Statistik und Quantitative Okonomik, Universität der Bundeswehr Hamburg, Hamburg, F.R.G.) data sheet (b. 1/23/40; Martin Schader)
found: NATO Advanced Research Workshop on Data, Expert Knowledge, and Decisions (1989 : Hamburg, Germany). Knowledge, data, and computer-assisted decisions, c1990:CIP t.p. (Schader, Martin) data sheet (b. 1/23/49)
found: Phone call to pub., 5/21/90(Martin Schader; confirms b. date as 1/23/49; earlier cite as 1940 is an error)