@article{ZNSL_1979_83_a3,
     author = {M. L. Katkov},
     title = {Generalization of istratescu's theorem on contractive mappings in metric spaces},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {73--82},
     publisher = {mathdoc},
     volume = {83},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1979_83_a3/}
}