Original Patents, 1936-1953
European patents, 1940-1953.
U.S. patents, 1936-1941.
U.S. patents, 1942-1943.
Canadian patents, 1941.
Canadian patents, 1941-1943.
British Government Patent Publications, 1855-1939
Scope and Content Note
1855-1936.
1926-1930.
1932-1937.
1937-1939.