@article{10_4153_CMB_1974_042_3,
     author = {Hsieh, Tsu-Teh and Tan, Kok-Keong},
     title = {Periodic {Points} and {Contractive} {Mappings}},
     journal = {Canadian mathematical bulletin},
     pages = {209--211},
     year = {1974},
     volume = {17},
     number = {2},
     doi = {10.4153/CMB-1974-042-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1974-042-3/}
}