References
- Ahuja , R. K. , Magnanti , T. L. and Orlin , J. B. 1993 . Network Flows: Theory, Algorithms, and Applications , N.J Englewood Cliffs : Prentice-Hall .
- Chvátal , V. 1983 . Linear Programming , New York : W.H. Freeman .
- Cottle , B. 1978 . The Penguin Dictionary of Surnames , 2 , Middlesex, , England : Penguin Books, Ltd., Harmondsworth .