@article{01863422, title = {A lantern lemma.}, journal = {Geometry \& Topology}, volume = {6}, year = {2002}, pages = {1179-1195}, doi = {10.2140/agt.2002.2.1179}, zbl = {1022.57001}, language = {en}, url = {http://dml.mathdoc.fr/item/01863422} }
Margalit, Dan. A lantern lemma.. Geometry & Topology, Tome 6 (2002) pp. 1179-1195. doi : 10.2140/agt.2002.2.1179. http://gdmltest.u-ga.fr/item/01863422/