Cite

Map showing controlled canals in England & Wales.

MLA

Map Showing Controlled Canals in England & Wales. Ordnance Survey, 1918. https://collections.library.yale.edu/catalog/15352160.

APA, 6th edition

Map showing controlled canals in England & Wales. (1918). [Maps]. Ordnance Survey, https://collections.library.yale.edu/catalog/15352160.