@article{CG_2007___48_7_0,
     author = {Roegel, Denis},
     title = {Sph\`eres, grands cercles et~parall\`eles},
     journal = {Cahiers GUTenberg},
     pages = {7--22},
     publisher = {Association GUTenberg},
     number = {48},
     year = {2007},
     language = {fr},
     url = {http://www.numdam.org/item/CG_2007___48_7_0/}
}