TY - Chinese Journal of Management Science A1 - XIONG He-ping T1 - The Properties of Portfolio’s Covariance Matrix and The Optimal Portfolio Selection Y1 - 2002-04-28 JF - Chinese Journal of Management Science JO - Chinese Journal of Management Science SP - 12 EP - 14 VL - IS - 2 UR - http://www.zgglkx.com N1 - ER -