David Rojas-Rueda, Audrey de Nazelle, Marko Tainio, Mark J Nieuwenhuijsen
Rojas-Rueda D, de Nazelle A, Tainio M, Nieuwenhuijsen M J.
The health risks and benefits of cycling in urban environments compared with car use: health impact assessment study
BMJ 2011; 343 :d4521
doi:10.1136/bmj.d4521