MLA

Jefferys, Thomas, d. 1771. A map of the island of St. John in the Gulf of St. Laurence [cartographic material] : divided into counties & parishes and the lots as granted by government : to which are added the soundings round the coast & harbours / improv'd from the late survey of C. BRBL_00688. April 6, 1775.. https://collections.library.yale.edu/catalog/15825306.

APA, 6th edition

Jefferys, Thomas, d. 1771. (["BRBL_00688"])(April 6, 1775.)[A map of the island of St. John in the Gulf of St. Laurence [cartographic material] : divided into counties & parishes and the lots as granted by government : to which are added the soundings round the coast & harbours / improv'd from the late survey of C]. https://collections.library.yale.edu/catalog/15825306.