Revision cycles 1:50,000 topographic mapping, [Canada] = Cycles de révision des cartes topographiques a l'échelle de 1:50,000, [Canada].
Canada.Surveys and Mapping Branch.
[Ottawa] : Dept. of Energy, Mines and Resources Surveys and Mapping Branch,
1980.
Cycles indicated for city, rural, wilderness & Arctic (& subarctic) areas.