Effects of Indian preference on employees of Indian agencies : hearings before the Subcommittee on Compensation and Employment Benefits of the Committee on Post Office and Civil Service, United States Senate, Ninety-fourth Congress, first session, on S. 509, to revise retirement benefits for certain employees of the Bureau of Indian Affairs and the Indian Health Service not entitled to Indian preference, provide greater opportunity for advancement and employment of Indians, and for other purposes, and S. 771, to assist certain employees of the United States in finding other employment in the civil service, June 18 and 19, 1975.