Acker, Veronique van, Patricia L. Mokhtarian, and Frank Witlox. “Going Soft: On How Subjective Variables Explain Modal Choices for Leisure Travel”. European Journal of Transport and Infrastructure Research 11, no. 2 (April 1, 2011). Accessed April 19, 2024. https://journals.open.tudelft.nl/ejtir/article/view/2919.