@article{MAN_1980__249_163403,
     author = {Dennis Johnson},
     title = {An {Abelian} {Quotient} of the {Mapping} {Class} {Group} ...g.},
     journal = {Mathematische Annalen},
     pages = {225--242},
     publisher = {mathdoc},
     volume = {249},
     year = {1980},
     zbl = {0409.57009},
     url = {http://geodesic.mathdoc.fr/item/MAN_1980__249_163403/}
}