@article{10_2140_agt_2015_15_3707,
     author = {Hughes, Mark C},
     title = {Braiding link cobordisms and non-ribbon surfaces},
     journal = {Algebraic and Geometric Topology},
     pages = {3707--3729},
     year = {2015},
     volume = {15},
     number = {6},
     doi = {10.2140/agt.2015.15.3707},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2015.15.3707/}
}