Limited air carrier certificates: hearings before a Subcommittee of the Committee on Interstate and Foreign Commerce, House of Representatives, Eighty-seventh Congress, first session, on H.R. 7318 and H.R. 7512, bills to amend the Federal Aviation Act of 1958, as amended, to provide for a class of supplemental air carriers, and for other purposes [and] H.R. 7679, a bill to amend the Federal Aviation Act of 1958, as amended, to provide for all-charter certificates of public convenience and necessity, June 20, 21, and 23, 1961.