Keefer, L. E. (1966). Urban travel patterns for airports, shopping centers, and industrial plants. Highway Research Board, Division of Engineering, National Research Council, National Academy of Sciences.
Chicago-viite (17. p.)Keefer, Louis E. Urban Travel Patterns for Airports, Shopping Centers, and Industrial Plants. Washington, D.C: Highway Research Board, Division of Engineering, National Research Council, National Academy of Sciences, 1966.
MLA-viite (9. p.)Keefer, Louis E. Urban Travel Patterns for Airports, Shopping Centers, and Industrial Plants. Highway Research Board, Division of Engineering, National Research Council, National Academy of Sciences, 1966.
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