@article{10_4153_CMB_1999_026_6,
     author = {Paeng, Seong-Hun and Yun, Jong-Gug},
     title = {Conjugate {Radius} and {Sphere} {Theorem}},
     journal = {Canadian mathematical bulletin},
     pages = {214--220},
     year = {1999},
     volume = {42},
     number = {2},
     doi = {10.4153/CMB-1999-026-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1999-026-6/}
}