@article{MASLO_1992__42_2_a9,
     author = {Tong, Jingcheng},
     title = {Internal, external boundaries and continuous mappings},
     journal = {Mathematica slovaca},
     pages = {215--221},
     publisher = {mathdoc},
     volume = {42},
     number = {2},
     year = {1992},
     mrnumber = {1170106},
     zbl = {0783.54011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1992__42_2_a9/}
}