Map of Lockhart River Basin, Great Slave Lake District, Northwest Territories : including the head waters of Thelon, Back and Coppermine Rivers / compiled, drawn and printed at the Topographical Survey of Canada.
MLA
Survey, Canada. Topographical. Map of Lockhart River Basin, Great Slave Lake District, Northwest Territories : Including the Head Waters of Thelon, Back and Coppermine Rivers / Compiled, Drawn and Printed at the Topographical Survey of Canada. Topographical Survey of Canada, 1925. https://collections.library.yale.edu/catalog/15536394.
APA, 6th edition
Survey, C. T. (1925). Map of Lockhart River Basin, Great Slave Lake District, Northwest Territories : including the head waters of Thelon, Back and Coppermine Rivers / compiled, drawn and printed at the Topographical Survey of Canada. [Maps]. Topographical Survey of Canada, https://collections.library.yale.edu/catalog/15536394.