Patent extension : hearing before Subcommittee No. 3 of the Committee on the Judiciary, House of Representatives, Eighty-fourth Congress, first session on H.R. 2128, a bill to authorize the extension of patents covering inventions whose practice was prevented or curtailed during certain emergency periods by service of the patent owner in the armed forces or by production controls : H.R. 3134 and H.R. 4700, bills to provide for extension of terms of patents where the use, exploitation, or promotion thereof was prevented, impaired, or delayed by causes due to war, national emergency, or other causes, March 9, 1955.