@article{10_2140_agt_2012_12_469,
     author = {Fiedorowicz, Zbigniew and Gubkin, Steven and Vogt, Rainer~M},
     title = {Associahedra and weak monoidal structures on categories},
     journal = {Algebraic and Geometric Topology},
     pages = {469--492},
     year = {2012},
     volume = {12},
     number = {1},
     doi = {10.2140/agt.2012.12.469},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2012.12.469/}
}