To control illegal migration : hearings before the Subcommittee on Immigration and Naturalization of the Committee on the Judiciary, United States Senate, Eighty-third Congress, second session on S. 3660, to make the employment, and related practices, of any alien known by an employer to have entered the United States illegally within 3 years thereof unlawful, and for other purposes and S. 3661, to provide for the seizure and forfeiture of any vessel or vehicle used in the transportation of any alien known by the owner thereof to have entered the United States illegally within 3 years thereof, and for other purposes, July 12, 13, and 14, 1954.