@article{GT_1999_3_1_a9,
     author = {Bartels, Arthur C and Teichner, Peter},
     title = {All two dimensional links are null homotopic},
     journal = {Geometry & topology},
     pages = {235--252},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {1999},
     doi = {10.2140/gt.1999.3.235},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/gt.1999.3.235/}
}