@article{10_4171_dm_469,
     author = {Peter Teichner and Rob Schneiderman},
     title = {Pulling apart 2-spheres in 4-manifolds},
     journal = {Documenta mathematica},
     pages = {941--992},
     year = {2014},
     volume = {19},
     doi = {10.4171/dm/469},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/dm/469/}
}