Bibliographical references Barbolla, Cerdá, Sanz (1991). Optimización matemática: teoría, ejemplos y contraejemplos. Ed. Espasa Calpe. Bazaraa, Jarvis (1977). Linear programming and network flows. J. Wiley. Bertsekas, D. (1987). Dynamic Programming. Deterministic and stochastic models. Prentice Hall. Caputo, M.R. (1990). "How to do comparative dynamics on the back of an envelope in optimal control theory". Journal of Economic Dynamics and Control. Vol. 14, nº 3/4, págs. 655-683. Chiang, A. (1987). Métodos fundamentales de Economía Matemática. 3ª edición. McGraw Hill. Duffin, Peterson y Zener (1967). Geometric Programming. J. Wiley. Frankling, J. (1980). Methods of Mathematical Economics. Springer Verlag. La France, Barney (1991). "The envelope theorem in dynamic optimization". Journal of Economic Dynamics and Control. Vol. 15, nº 2, págs. 355-385. Samuelson, P. (1947). Foundations of Economic Analysis. Harvard University Press. Silberberg, E. (1971). "The Le chatelier Principle as a Corollary to a Generalized Envelope Theorem". Journal of Economic Theory, 3; págs. 146-155. Silberberg, E. (1974). "A Revision of Comparative Statics Methodology in Economics, or, How to Do Economics on the Back of an Envelope". Journal of Economic Theory, 7. págs. 159-172. Silberberg, E. (1978). The structure of economics: a mathematical analysis. First edition. McGraw Hill. Silberberg, E. (1990). The structure of economics: a mathematical analysis. Second edition. McGraw Hill. Viner, J. (1932). "Cost Curves and Supply Curves". Zeitschrift fur nationalokonomie, 3; 1932. Reprinted in Readings in Price Theory (AEA). Wismer, Chattergy (1978). Introduction to nonlinear optimization. North Holland.