@article{10_4153_CJM_1966_087_x,
     author = {Whittaker, James V.},
     title = {A {Mountain-Climbing} {Problem}},
     journal = {Canadian journal of mathematics},
     pages = {873--882},
     year = {1966},
     volume = {18},
     number = {1},
     doi = {10.4153/CJM-1966-087-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1966-087-x/}
}