@article{10_2140_agt_2009_9_351,
     author = {Nikkuni, Ryo},
     title = {An intrinsic nontriviality of graphs},
     journal = {Algebraic and Geometric Topology},
     pages = {351--364},
     year = {2009},
     volume = {9},
     number = {1},
     doi = {10.2140/agt.2009.9.351},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2009.9.351/}
}