Balcombe, R., Rutherford, D., & Walmsley, D. (1973). A parametric model of inter-city passenger transport: An interim report. Transport and Road Research Laboratory.
Lua i Stíl Chicago (17ú heag.)Balcombe, R.J, D.J Rutherford, agus D.A Walmsley. A Parametric Model of Inter-city Passenger Transport: An Interim Report. Crowthorne, Eng: Transport and Road Research Laboratory, 1973.
Lua MLA (9ú heag.)Balcombe, R.J, et al. A Parametric Model of Inter-city Passenger Transport: An Interim Report. Transport and Road Research Laboratory, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.