%0 Journal Article %A S. L. Singh %A J. H. M. Whitfield %T Contractors and fixed points %J Colloquium Mathematicum %D 1987 %P 219-228 %V 55 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-55-2-219-228/ %R 10.4064/cm-55-2-219-228 %G en %F 10_4064_cm_55_2_219_228