P. Sveistrup, P. “Koopmans, T.: TANKER FREIGHT RATES AND TANKSHIP BUILDING. An Analyses Cyclical Fluctuations. Haarlem & London 1939”. Nationaløkonomisk tidsskrift 3 (January 1, 1940). Accessed December 5, 2025. https://tidsskrift.dk/nationaloekonomisktidsskrift/article/view/60080.