@article{SM_2002_193_3_a0,
     author = {S. I. Bogataya and S. A. Bogatyi and H. Zieschang},
     title = {Composites of open maps},
     journal = {Sbornik. Mathematics},
     pages = {311--327},
     publisher = {mathdoc},
     volume = {193},
     number = {3},
     year = {2002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2002_193_3_a0/}
}