@article{10_4153_CMB_1993_033_8,
     author = {Oda, Nobuyuki},
     title = {Pairings of {Homotopy} {Sets} {Over} and {Under} {B}},
     journal = {Canadian mathematical bulletin},
     pages = {231--240},
     year = {1993},
     volume = {36},
     number = {2},
     doi = {10.4153/CMB-1993-033-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1993-033-8/}
}