1. [Nurses in gas masks at the trenches, Germany] Publication: [United States? : s.n., 1916] Subject(s): NursesRespiratory Protective DevicesWorld War I
2. His mask: keeps him on the job Publication: [Washington, D.C.] : U.S. Public Health Service : U.S. G.P.O., 1942 Subject(s): Respiratory Protective DevicesLung Diseases -- prevention & controlHealth Behavior
