Tuells A, Arana A, Perez-Gutthann S, García-Rodríguez LA. El Proyecto BIFAP. Inv Clin Farm. 2003;0:25-6.
Reed (Earnshaw) SR, Reed JH, Stuhldreher TJ. Transaction costs, taxes, and portfolio revision. J Contemp Bus Issue. 1997;5:40-8.