APA

United States, . (1949). Railroad safety: supplemental hearings, 81st Congress, 1st session, on H.R. 378, H.R. 530, Aug. 4-9, 1949. [Washington, D.C.]: .

Chicago

United States, . 1949. Railroad safety: supplemental hearings, 81st Congress, 1st session, on H.R. 378, H.R. 530, Aug. 4-9, 1949. [Washington, D.C.]: .

Harvard

United States, . (1949). Railroad safety: supplemental hearings, 81st Congress, 1st session, on H.R. 378, H.R. 530, Aug. 4-9, 1949. [Washington, D.C.]: .

MLA

United States, . Railroad safety: supplemental hearings, 81st Congress, 1st session, on H.R. 378, H.R. 530, Aug. 4-9, 1949. [Washington, D.C.]: . 1949.