Columbia subject headings:
World War, 1939-1945--Campaigns--Eastern Front.
World War, 1939-1945--Engineering and construction.
Harvard subject headings:
World War, 1939-1945--Campaigns, Eastern.
World War, 1939-1945--Campaigns--Eastern Front.
World War, 1939-1945--Engineering and construction.
Princeton subject headings:
World War, 1939-1945--Campaigns--Eastern Front.
World War, 1939-1945--Engineering and construction.