CHÉRON, André. Les Éches Artistiques, un traité sur le problème et l' étude, Lausanne, Payot, 1934, 8°, FIRST EDITION, diagrams, original cloth; Lehr-und Handbuch der Endspiele, Berlin, Siegfried Engelhardt, 1952-70, 4 vols., 8°, FIRST EDITION, half tone portrait in vol. I, diagrams, original cloth -- NIEMEIJER, M. Bloemlezing van Nederlandsche Schaakproblemen uit der Jaren 1792-1933, Amsterdam, N.V. Swets & Zetlinger, 1934, 8°, FIRST EDITION, PRESENTATION COPY, half title inscribed: "Dr. Robert Blass vom Verfasser 23. 8. 1935", half tone portrait of Zuylen van Nyevelt, diagrams, original wrappers; and approximately 60 other books and pamphlets, 1920's to 50's, most on problems.