2KRISHNA PALEPU. Diversification Strategy Profit Performance and the Entropy Measure[J]. Strategic Management Journal, 1985, (6):239-255.
3CHARLES W L HILL, MICHAEL A HITT, ROBERTE HOSKISSON. Coo perative versus Competitive Structures in Related and Unrelated Diversified Firms [J]. Organization Science, 1992,3(4):501-592.