Watts, P. (1984). The potential for postbus development. Transport and Road Research Laboratory.
Chicago-referens (17:e uppl.)Watts, P.F. The Potential for Postbus Development. Crowthorne, Berkshire: Transport and Road Research Laboratory, 1984.
MLA-referens (9:e uppl.)Watts, P.F. The Potential for Postbus Development. Transport and Road Research Laboratory, 1984.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.