US Army Armor Center. (1993). Preventive maintenance: Your 81-MM and 4.2-inch mortars. US Army Armor Center.
Chicago Style (17th ed.) CitationUS Army Armor Center. Preventive Maintenance: Your 81-MM and 4.2-inch Mortars. Fort Knox, KY: US Army Armor Center, 1993.
MLA (9th ed.) CitationUS Army Armor Center. Preventive Maintenance: Your 81-MM and 4.2-inch Mortars. US Army Armor Center, 1993.
Warning: These citations may not always be 100% accurate.