@article{10_2140_agt_2008_8_1499,
     author = {Sakai, Keiichi},
     title = {Nontrivalent graph cocycle and cohomology of the long knot space},
     journal = {Algebraic and Geometric Topology},
     pages = {1499--1522},
     year = {2008},
     volume = {8},
     number = {3},
     doi = {10.2140/agt.2008.8.1499},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2008.8.1499/}
}