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.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)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.
Trích dẫn kiểu MLA (xuất bản lần thứ 9)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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