United States. War Department. (1931). Mobile artillery materiel: 155-mm. howitzer materiel, M1917 and M1918. GPO.
Chicago Style (17th ed.) CitationUnited States. War Department. Mobile Artillery Materiel: 155-mm. Howitzer Materiel, M1917 and M1918. [Washington]: GPO, 1931.
MLA (9th ed.) CitationUnited States. War Department. Mobile Artillery Materiel: 155-mm. Howitzer Materiel, M1917 and M1918. GPO, 1931.
Warning: These citations may not always be 100% accurate.