Gaya APA

Hopkins, John B.. (1974). Technological aspects of public responsibility for grade crossing protection . : TRB.

Gaya Chicago

Hopkins, John B.. Technological aspects of public responsibility for grade crossing protection. : TRB, 1974. Chart.

Gaya MLA

Hopkins, John B.. Technological aspects of public responsibility for grade crossing protection. : TRB, 1974. Chart.

Gaya Turabian

Hopkins, John B.. Technological aspects of public responsibility for grade crossing protection. : TRB, 1974. Chart.