[1]B. T. Sawik, PMI, т. 167, вып. 2, сс. 306-308, фев. 2006.

[1]B. T. Sawik, "The Modification of Markowitz Portfolios Made for Stocks from the Warsaw Stock Exchange", PMI, vol. 167, no. 2, pp. 306-308, Feb. 2006.