%0 Journal Article %A Tsuboi, Takashi %T On 2-cycles of $B~{\rm Diff}(S^1)$ which are represented by foliated $S^1$-bundles over $T^2$ %J Annales de l'Institut Fourier %D 1981 %P 1-59 %V 31 %N 2 %I Institut Fourier %U https://doi.org/10.5802/aif.828 %R 10.5802/aif.828 %G en %F AIF_1981__31_2_1_0