1. Schaible, S., A Note on the Sum of a Linear and Linear-Fractional Function, Naval Research Logistics Quarterly, Vol. 24, pp. 691–693, 1977.
2. Craven, B. D., Fractional Programming, Sigma Series in Applied Mathematics, Heldermann Verlag, Berlin, Germany, Vol. 4, 1988.
3. Martein, L., Maximum of the Sum of a Linear Function and a Linear-Fractional Function, Rivista di Matematica per le Scienze Economiche e Sociali, Vol. 8, pp. 13–20, 1985 (in Italian).
4. Cambini, A., Martein, L., and Schaible, S., On Maximizing a Sum of Ratios, Journal of Information and Optimization Sciences, Vol. 10, pp. 65–79, 1989.
5. Schaible, S., Fractional Programming, Handbook of Global Optimization, Edited by R. Horst and P. M. Pardalos, Kluwer Academic Publishers, Dordrecht, Netherlands, pp. 495–608, 1995.