@article{10_4153_CMB_1993_034_5,
     author = {Pakula, Lewis},
     title = {Regions {Cut} by {Arrangements} of {Topological} {Spheres}},
     journal = {Canadian mathematical bulletin},
     pages = {241--244},
     year = {1993},
     volume = {36},
     number = {2},
     doi = {10.4153/CMB-1993-034-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1993-034-5/}
}