1. Berman, A., Plemmons, R.J.: Nonnegative Matrices in the Mathematical Sciences. New York, Academic Press 1979
2. Bidard, C: Prix, reproduction, rareté. Paris: Dunod 1991 (Chapter 10, p.113)
3. Chander, P.: A simple proof of the nonsubstitution theorem. Quarterly Journal of Economics 88, 698–701 (1974)
4. Fujimoto, T.: Nonlinear Leontief models in abstract spaces. Journal of Mathematical Economics 15, 151–156 (1986)
5. Fujimoto, T., Silva, J., Villar, A.: An input-output model with joint production, mimeograph. Department of Fundamental Analysis of Economics, University of Alicante 2002