MLA

Mercator, Gerhard, 1512-1594. Wirtenberg Ducatus / [cartographic material] / per Gerardum Meractorem, cum privilegio.. BRBL_00138. [1636]. https://collections.library.yale.edu/catalog/15483018.

APA, 6th edition

Mercator, Gerhard, 1512-1594. (["BRBL_00138"])([1636])[Wirtenberg Ducatus / [cartographic material] / per Gerardum Meractorem, cum privilegio.]. https://collections.library.yale.edu/catalog/15483018.