Kyong Joo Oh Tae Yoon Kim Sung-Hwan Min Hyoung Yong Lee Portfolio algorithm based on portfolio beta using genetic algorithm. 527-534 2006 30 Expert Syst. Appl. 3 http://dx.doi.org/10.1016/j.eswa.2005.10.010 db/journals/eswa/eswa30.html#OhKML06