MLA

Valck, G. (Gerard), 1651-1726, cartographer. Treverensis regio archiepiscopatus electoratusque titulo insignus : quae per suas divisa praefecturas comitatum Manderscheit complectitur. ca. 1702]. https://collections.library.yale.edu/catalog/16618358.

APA, 6th edition

Valck, G. (Gerard), 1651-1726, cartographer. (ca. 1702])[Treverensis regio archiepiscopatus electoratusque titulo insignus : quae per suas divisa praefecturas comitatum Manderscheit complectitur]. https://collections.library.yale.edu/catalog/16618358.