@article{CRMATH_2014__352_1_59_0,
     author = {Biswas, Indranil and Neumann, Frank},
     title = {Atiyah sequences, connections and characteristic forms for principal bundles over groupoids and stacks},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {59--64},
     publisher = {Elsevier},
     volume = {352},
     number = {1},
     year = {2014},
     doi = {10.1016/j.crma.2013.10.038},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2013.10.038/}
}