J. D. Daniels and J. Bracker. Profit Performance: Do foreign operations make a difference? // Management International Review 29 (1) 1987. P. 46–56; Michael A. Hitt, R. E. Hoskisson and Hicheon Kim. International Diversification: Effects on Innovation and Firm Performance in Product Diversified Firms // Academy of Management Journal 40 (4) 1997. P. 767–798; Stephen Tallman and L. Jaitao. Effects of International Diversity and Product Diversity on the Performance of Multinational Firms // Academy of Management Journal 39 (1) 1996. P. 179–196.