@article{MM2_1986__56_155153,
     author = {Robert Hardt and Fang-Hua Lin},
     title = {A {Remark} on {H1} {Mappings.}},
     journal = {Manuscripta mathematica},
     pages = {1--10},
     publisher = {mathdoc},
     volume = {56},
     year = {1986},
     zbl = {0618.58015},
     url = {http://geodesic.mathdoc.fr/item/MM2_1986__56_155153/}
}