Visscher, Nicolaes.  "S.R.I. Sueviae Circulus atq[ue] Ducatus una cum insertis et adjacentibus Regionibus, accuratissime in earundem particulares provincias divisum."  Map.  1705.  Norman B. Leventhal Map & Education Center,  https://collections.leventhalmap.org/search/commonwealth:cj82kw69t (accessed May 23, 2019).