@article{AIF_1981__31_2_1_0, author = {Tsuboi, Takashi}, title = {On 2-cycles of $B~{\rm Diff}(S^1)$ which are represented by foliated $S^1$-bundles over $T^2$}, journal = {Annales de l'Institut Fourier}, pages = {1--59}, publisher = {Institut Fourier}, volume = {31}, number = {2}, year = {1981}, doi = {10.5802/aif.828}, zbl = {0439.57018}, mrnumber = {84b:57019}, language = {en}, url = {http://archive.numdam.org/articles/10.5802/aif.828/} }