J. D. Sepúlveda Chaverra, L. Meriño Stand, M. J. Vélez Murillo, and C. Flórez Echenique, “ACTION STRATEGIES AND COMPETITIVE POTENTIAL OF CUSTOMS BROKERAGE FIRMS IN CARTAGENA DE INDIAS”, LEBRET, vol. 4, no. 4, pp. 47–69, Jan. 2012.