MLA

Oporto (Porto) [Cartographic Material] / Drawn by W.B. Clarke, Archt. ; Printed [and] Engraved by J. Henshall. Published by Baldwin & Cradock, 0AD. https://collections.library.yale.edu/catalog/15487364.

APA, 6th edition

Oporto (Porto) [cartographic material] / drawn by W.B. Clarke, archt. ; printed [and] engraved by J. Henshall. (0 C.E.). [Maps]. Published by Baldwin & Cradock, https://collections.library.yale.edu/catalog/15487364.