@article{10_4153_CJM_1976_116_5,
     author = {Leighton, Walter},
     title = {Some {Comparison} {Theorems} for {Conjugate} {And} {\ensuremath{\sigma}-Points}},
     journal = {Canadian journal of mathematics},
     pages = {1172--1179},
     year = {1976},
     volume = {28},
     number = {6},
     doi = {10.4153/CJM-1976-116-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-116-5/}
}