APA-referens (7:e uppl.)

Wren, A. (1971). Computers in transport planning and operation. Ian Allan.

Chicago-referens (17:e uppl.)

Wren, Anthony. Computers in Transport Planning and Operation. Londres: Ian Allan, 1971.

MLA-referens (9:e uppl.)

Wren, Anthony. Computers in Transport Planning and Operation. Ian Allan, 1971.