O.H, .-. (1968) “Kaplan, Jacob J., The Challenge of Foreign Aid - Policies, Problems, and Possibilities, Frederick A. Praeger, New York, 1967 (andra tryckn. 1968) - Praeger Series on International Economics and Development”., Ledelse og Erhvervsøkonomi, 32. Tilgængelig hos: https://tidsskrift.dk/ledelseogerhvervsoekonomi/article/view/34464 (Set: 6 december 2025).