Retirement of Employees Engaged in Hazardous Occupations in Places of Detention: Hearing Before the Committee on Post Office and Civil Service, House of Representatives, Eighty-fourth Congress, Second Session, on S. 65, H. R. 484, H. R. 6273, and H. R. 7179, Bills to Amend Section 1 (d) of the Civil Service Retirement Act of May 29, 1930, as Amended. June 12, 1956