TY  - JOUR
AU  - Williams, Gordon
TI  - Petrie Schemes
JO  - Canadian journal of mathematics
PY  - 2005
SP  - 844
EP  - 870
VL  - 57
IS  - 4
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CJM-2005-033-6/
DO  - 10.4153/CJM-2005-033-6
ID  - 10_4153_CJM_2005_033_6
ER  -