MLA

Valck, G. (Gerard), 1651 or 1652-1726. Archiepiscopatus Coloniensis, ducatibus Iuliacensi et Montensi intermedius [cartographic material] : queis in septentrionem adjacent Geldria Hispanica, ac comitatus Mursanus / prostant penes Gerardum Valk.. ca. 1702?]. https://collections.library.yale.edu/catalog/16618359.

APA, 6th edition

Valck, G. (Gerard), 1651 or 1652-1726. (ca. 1702?])[Archiepiscopatus Coloniensis, ducatibus Iuliacensi et Montensi intermedius [cartographic material] : queis in septentrionem adjacent Geldria Hispanica, ac comitatus Mursanus / prostant penes Gerardum Valk.]. https://collections.library.yale.edu/catalog/16618359.