“CASE STUDY. HOW TO DEVELOP AN INVESTMENT PORTFOLIO CONSIDERING THE DIFFERENT ALTERNATIVES THAT VOLUNTARY PENSION FUNDS OFFER IN COLOMBIA: THE CASE OF SKANDIA (Article published in Spanish)”, estud.gerenc., vol. 25, no. 113, pp. 229–242, Dec. 2009, doi: 10.1016/S0123-5923(09)70097-X.