Map of the County of Buckingham ... by J. & C. Greenwood. Engraved by J. & C. Walker.
MLA
Map of the County of Buckingham ... by J. & C. Greenwood. Engraved by J. & C. Walker. Greenwood & Co., 1834. https://collections.library.yale.edu/catalog/15309150.
APA, 6th edition
Map of the County of Buckingham ... by J. & C. Greenwood. Engraved by J. & C. Walker. (1834). [Maps]. Greenwood & Co., https://collections.library.yale.edu/catalog/15309150.