[1] E. J. Elton, M. J. Gruber, S. J. Brown and W. N. Goetzmann, Modern Portfolio Theory and Investment Analysis (9th Ed), John Wiley & Sons, Asia, 2014, Chapter 5.
[2] G. Grimmett and D. Stirzaker, Probability and Random Processes (3rd Ed), Oxford University Press, New York, 2001, p.65.
[3] C. Huang and R. H. Litzenberger, Foundations for Financial Economics, North-Holland, New York, 1988, Chapter 3.
[4] D. G. Luenberger, Investment Science (2nd Ed), Oxford University Press, New York, 2013,Section 6.8.
[5] H. M. Markowitz, Portfolio Selection, Journal of Finance, 7 (1952), 77-91.