APA
Chapman J., Andre P., . (1785). A Map of the County of Essex from an actual survey taken in MDCCLXXII: LXXIII & MDCCLXXIV. By John Chapman & Peter Andre. (A Plan of Colchester.--Harwich Harbour.) 4 miles [ = 200 mm]. Colchester: W. Keymer.
Chicago
Chapman John, Andre Peter, . 1785. A Map of the County of Essex from an actual survey taken in MDCCLXXII: LXXIII & MDCCLXXIV. By John Chapman & Peter Andre. (A Plan of Colchester.--Harwich Harbour.) 4 miles [ = 200 mm]. Colchester: W. Keymer.
Harvard
Chapman J., Andre P., . (1785). A Map of the County of Essex from an actual survey taken in MDCCLXXII: LXXIII & MDCCLXXIV. By John Chapman & Peter Andre. (A Plan of Colchester.--Harwich Harbour.) 4 miles [ = 200 mm]. Colchester: W. Keymer.
MLA
Chapman John, Andre Peter, . A Map of the County of Essex from an actual survey taken in MDCCLXXII: LXXIII & MDCCLXXIV. By John Chapman & Peter Andre. (A Plan of Colchester.--Harwich Harbour.) 4 miles [ = 200 mm]. Colchester: W. Keymer. 1785.