@article{10_4153_CJM_1971_049_6,
     author = {Schirmer, Helga},
     title = {Biconnected {Multifunctions} of {Trees} which have an end {Point} as {Fixed} {Point} or {Coincidence}},
     journal = {Canadian journal of mathematics},
     pages = {461--467},
     year = {1971},
     volume = {23},
     number = {3},
     doi = {10.4153/CJM-1971-049-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1971-049-6/}
}