MAJID, M. S. A.; MAULANA, H. A Comparative Analysis of the Productivity of Islamic and Conventional Mutual Funds in Indonesia: Data Envelopment Analysis (DEA) and General Least Square (GLS) Approaches. Gadjah Mada International Journal of Business, v. 14, n. 2, p. 183 - 208, 1 May 2012.