1. An Application of Markov Modeling to the Student Flow in Higher Education in Sudan;R Y Adam;International Journal of Science and Research (IJSR),2015
2. Contribuci�n al estudio del impacto de la gamificaci�n en el sector tur�stico: promoci�n de comportamientos proambientales;L Aguiar-Castillo;VII Jornadas Iberoamericanas de Innovaci�n Educativa en el �mbito de las TIC y las TAC: InnoEducaTIC 2020,2020
3. Impure Altruism and Donations to Public Goods: A Theory of WARM-GLOW GIVING;J Andreoni;The Economic Journal,1990
4. Privately Provided Public Goods in A Large Economy: The Limits of Altruism;J Andreoni;Journal of Public Economics,1988