Ramírez, J. C., and R. Sandoval Saavedra. “A Proposal to Evaluate Stock Performance Forecasts When Empirical Distributions Are Not Normally Stationary”. Estudios Económicos De El Colegio De México, vol. 18, no. 2, July 2003, pp. 237-7, doi:10.24201/ee.v18i2.182.