Columbia subject headings:
Harvard subject headings:
Animal welfare--History--20th century.
Animals--War use--History--20th century.
World War, 1914-1918
World War, 1939-1945
Princeton subject headings:
Animal welfare--History--20th century.
Animals--War use--History--20th century.
World War, 1914-1918.
World War, 1939-1945.