Runhaar, Hens, Rob van der Heijden, and Bart Kuipers. “Flexibility of Freight Transport Sectors: An Exploration of Carriers’ Responses to External Pressure on Prices and Service”. European Journal of Transport and Infrastructure Research 2, no. 1 (January 1, 2002). Accessed April 20, 2024. https://journals.open.tudelft.nl/ejtir/article/view/3674.