Westerlund, Y., A. Ståhl, G. Carlsson, and B. Stålner. “Servicelinje Eller Flextrafik – när, Var, Hur?”. Proceedings from the Annual Transport Conference at Aalborg University, vol. 11, no. 1, Dec. 2004, doi:10.5278/ojs.td.v11i1.4961.