MLA

Jefferys, Thomas, d. 1771. The western coast of Louisiana and the coast of New Leon / by Thos. Jefferys, geographer to His Majesty.. BRBL_00523. 1794. https://collections.library.yale.edu/catalog/15811449.

APA, 6th edition

Jefferys, Thomas, d. 1771. (["BRBL_00523"])(1794)[The western coast of Louisiana and the coast of New Leon / by Thos. Jefferys, geographer to His Majesty.]. https://collections.library.yale.edu/catalog/15811449.