Greening, P. A. K., & Smith, P. G. (1980). A survey of recreational traffic in the Yorkshire Dales. Access and Mobility Division, Transport and Road Research Laboratory.
Lua i Stíl Chicago (17ú heag.)Greening, P. A. K., agus P. G. Smith. A Survey of Recreational Traffic in the Yorkshire Dales. Crowthorne, Berk: Access and Mobility Division, Transport and Road Research Laboratory, 1980.
Lua MLA (9ú heag.)Greening, P. A. K., agus P. G. Smith. A Survey of Recreational Traffic in the Yorkshire Dales. Access and Mobility Division, Transport and Road Research Laboratory, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.