field manual Operations of engineer field units field manual Corps of engineers : construction and routes of communication field manual Military police in towns and cities field manual Air navigation / prepared under direction of the chief of the air corps field manual Weather field manual Reviews and inspection / Prepared under direction of the chief of the air corps field manual 81-MM mortar, MI / Prepared under direction of the chief of infantry field manual Barrage balloon : operation of matériel and employment of personnel field manual Watermanship field manual 81-MM mortar squad and platoon field manual 75-mm tank gun M 2 : (mounted in medium tank M 3) Permits for work in navigable waters / Corps of engineers ; Department of the army