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HugodeGrootGrollobsidiocvmannexisanniMDCXXVII MG .tif Detailed diagram for the moat of fortress Diagram voor een fortgracht PDArt DVorm Peace Palace Library collection Hugo de Groot Groll obsidio cvm annexis anni DC XXVII Hvg Grotio auctore Publisher Amstelredami apud Gvilielmvm Blaevw Printer Blaeu Willem Jansz Amsterdam Institution