@article{IM_1993__111_1_144076,
     author = {Shigeyuki Morita},
     title = {The extension of {Johnson's} homomorphism form the {Torelli} group to the mapping class group.},
     journal = {Inventiones mathematicae},
     pages = {197--224},
     publisher = {mathdoc},
     volume = {111},
     number = {1},
     year = {1993},
     zbl = {0787.57008},
     url = {http://geodesic.mathdoc.fr/item/IM_1993__111_1_144076/}
}