[For the entire collection see Zbl 0699.00032.] The author defines a general notion of a foliated groupoid over a foliation with singularities, within the framework of a (known) general notion of a differentiable structure. Then, he generalizes the classical correspondence between the subalgebras of Lie algebras and the subgroups of the corresponding Lie groups for this type of pseudogroups.
@article{702165, title = {Foliated groupoids}, booktitle = {Proceedings of the Winter School "Geometry and Physics"}, series = {GDML\_Books}, publisher = {Circolo Matematico di Palermo}, address = {Palermo}, year = {1990}, pages = {[127]-149}, mrnumber = {MR1061795}, zbl = {0707.57016}, url = {http://dml.mathdoc.fr/item/702165} }
Lisiecki, Krzysztof. Foliated groupoids, dans Proceedings of the Winter School "Geometry and Physics", GDML_Books, (1990), pp. [127]-149. http://gdmltest.u-ga.fr/item/702165/