Engebretsen, Øystein, and Karl-Erik Hagen. “Geografisk-økonomisk Modellsystem for Beregning Av Transportomfang Og Kostnader Ved Busstransport Mv Av Skolebarn”. Proceedings from the Annual Transport Conference at Aalborg University 4, no. 1 (December 31, 1997). Accessed April 28, 2024. https://journals.aau.dk/index.php/td/article/view/4051.