Megalithic tomb O1 near Steenwijkerwold, drawing by Petrus Camper, 1781
Petrus Camper (1722-1789)
1781
Jan Albert Bakker: <i>Megalithic Research in the Netherlands, 1547–1911. From ‘Giant's Beds’ and ‘Pillars of Hercules’ to accurate investigations.</i> Sidestone Press, Leiden 2010, <a href="//commons.wikimedia.org/wiki/Special:BookSources/9789088900341" title="Special:BookSources/9789088900341">ISBN 9789088900341</a>, fig. 27