Federal motor vehicle safety standard no. 121, air brake systems : hearings before the Subcommittee on Governmental Efficiency and the District of Columbia of the Committee on Governmental Affairs, United States Senate, Ninety-fifth Congress, first [ and second] session ...
United States.Congress.Senate.Committee on Governmental Affairs.Subcommittee on Governmental Efficiency and the District of Columbia.
Washington : U.S. Print. Off.,
1978.
Hearings held December 6, 1977.
Air brakes.
Motor vehicles