MLA

of Canada, Topographical Survey. Map of Alberta : Showing Elevations. Topographical Survey of Canada, 1923. https://collections.library.yale.edu/catalog/15536047.

APA, 6th edition

of Canada, T. S. (1923). Map of Alberta : showing elevations. [Maps]. Topographical Survey of Canada, https://collections.library.yale.edu/catalog/15536047.