Jakob Philipp Hackert, A Rocky Landscape at Civita Castellana, 1776, Brush and brown wash over graphite; framing lines in pen and brown ink, The Metropolitan Museum of Art, New York. https://dartabase.art/cite/met/334882

Jakob Philipp Hackert, Blick auf Sankt Peter in Rom, 1774, Öl auf Leinwand, Städel Museum, Frankfurt am Main. https://dartabase.art/cite/staedel/1537