1931.9-1933.8 1931.9-1937.6 1931.9-1937.7 1931.4-1931.7 1931.1-1931.3 1931.1-1931.4 1931.2-1931.3 1931.4-1931.6 1931.5-1945.8 1931.7-1931.9