1:50 000 topographic data in digital form : internal working document : [Canada] = 1:50 000 données topographiques sous forme numérique : document de travail interne : [Canada].
Canada.Surveys and Mapping Branch.
[Ottawa] : Canada, Dept. of Energy, Mines, and Resources, Surveys and Mapping Branch,
c1982.
"01-04-82."
Digital mapping.