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[http://www.nga.gov/content/ngaweb/research/casva/research-projects.html A Project of the National Gallery of Art, Center for Advanced Study in the Visual Arts ]
Rheum Palmaatum Linn., drawn by William de la Cour (d. 1767) and Samuel Bard; engraved by Andrew Bell, from Philosophical Transactions, Giving Some Account of the Present Undertakings, Studies, and Labours, of the Ingenious, in many Considerable Parts of the World...For the Year 1765 (London Royal Society, 1766), vol. 55, Plate XIII