International Road Federation. (2001). World road statistics: Data .. IRF.
Cita Chicago Style (17a ed.)International Road Federation. World Road Statistics: Data .. Vernier [u.a.]: IRF, 2001.
Cita MLA (8a ed.)International Road Federation. World Road Statistics: Data .. IRF, 2001.
Precaución: Estas citas no son 100% exactas.