signed and dated at bottom left in graphite: J. A. Klein fec. 1820 a Tivoli; verso, two graphite sketches: a fortress with two crenellated towers of different heights; a bridge
(sale, Hollstein und Puppel, Berlin, 26 February 1932, no. 119). (Galerie Barrsch & Chariau, Munich) 1980. Wolfgang Ratjen, Munich; purchased 2007 by NGA.
- German Master Drawings from the Wolfgang Ratjen Collection, 1580 - 1900, NGA, 2010: 36, 37, no. 65, under no. 41.