From BR Bullpen
1943 Baseball, best known as the Commissioner's Guide or Landis Guide for its origin in the Commissioner's Office, was the official Baseball Guide for that year. It was 736 pages long, with rules, illustrations, and a variety of articles on baseball in 1942. Due to wartime shortages, the Commissioner's Office was not able to acquire paper for a 1944 edition. Official Baseball replaced the Commissioner's Guide in 1945.
The Baseball Research Handbook, SABR, first published 1987