@article{MAN_1994__300_2_165263,
     author = {Loukas Grafakos and Richard Rochberg},
     title = {Compensated compactness and the {Heisenberg} group.},
     journal = {Mathematische Annalen},
     pages = {451--462},
     publisher = {mathdoc},
     volume = {300},
     number = {2},
     year = {1994},
     zbl = {0819.43006},
     url = {http://geodesic.mathdoc.fr/item/MAN_1994__300_2_165263/}
}