@article{10_21136_CMJ_1992_128369,
     author = {Pt\'ak, Vlastimil and Vrbov\'a, Pavla},
     title = {Contractive couplings},
     journal = {Czechoslovak Mathematical Journal},
     pages = {657--673},
     publisher = {mathdoc},
     volume = {42},
     number = {4},
     year = {1992},
     doi = {10.21136/CMJ.1992.128369},
     mrnumber = {1182198},
     zbl = {0783.47007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1992.128369/}
}