@article{SIGMA_2014_10_a87,
     author = {Bartosz Zieli\'nski},
     title = {Piecewise {Principal} {Coactions} of {Co-Commutative} {Hopf} {Algebras}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2014},
     volume = {10},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2014_10_a87/}
}