@article{10_4153_CJM_1976_037_2,
     author = {Anderson, Tim and Kleinfeld, Erwin},
     title = {A {Classification} of {2-Varieties}},
     journal = {Canadian journal of mathematics},
     pages = {348--364},
     year = {1976},
     volume = {28},
     number = {2},
     doi = {10.4153/CJM-1976-037-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-037-2/}
}