Christian Gottlieb Ludwig. Mezzotint by J. J. Haid after E. G. Haussmann. https://www.rawpixel.com/image/13989669/christian-gottlieb-ludwig-mezzotint-haid-after-haussmannFree Image from public domain licenseCarlo Guattani. Line engraving by G. Marcucci after G. Cleter. https://www.rawpixel.com/image/14016464/carlo-guattani-line-engraving-marcucci-after-cleterFree Image from public domain license