@article{AIF_1992__42_1-2_421_0,
     author = {Tsuboi, Takashi},
     title = {Area functionals and {Godbillon-Vey} cocycles},
     journal = {Annales de l'Institut Fourier},
     pages = {421--447},
     publisher = {Institut Fourier},
     address = {Grenoble},
     volume = {42},
     number = {1-2},
     year = {1992},
     doi = {10.5802/aif.1298},
     mrnumber = {94g:57032},
     zbl = {0759.57019},
     language = {en},
     url = {http://archive.numdam.org/articles/10.5802/aif.1298/}
}