National Research Council. Transportation Research Board. Committee on Public Transportation Planning and Development. Subcommittee on Definitions. Urban Public Transportation Glossary. Edited by Benita H. Gray. Washington, D.C.: Transportation Research Board, National Research Council, 1989.

National Research Council. Transportation Research Board. Committee on Public Transportation Planning and Development. Subcommittee on Definitions. Urban Public Transportation Glossary. Edited by Benita H. Gray. Washington, D.C.: Transportation Research Board, National Research Council, 1989.