Johann Arnold Joseph Büttner. Lithograph by F. Jentzen, 1830, after F. Krüger. https://www.rawpixel.com/image/14013463/johann-arnold-joseph-buttner-lithograph-jentzen-1830-after-krugerFree Image from public domain licenseJohann Wendt. Lithograph by F. Jentzen, 183-, after F. Krüger. https://www.rawpixel.com/image/13997403/johann-wendt-lithograph-jentzen-183-after-krugerFree Image from public domain licenseDietrich Wilhelm Heinrich Busch. Lithograph by F. Jentzen after F. Krüger. https://www.rawpixel.com/image/13971737/dietrich-wilhelm-heinrich-busch-lithograph-jentzen-after-krugerFree Image from public domain licenseHenrich Steffens. Lithograph by F. Jentzen, 1828, after F. Krüger. https://www.rawpixel.com/image/13992084/henrich-steffens-lithograph-jentzen-1828-after-krugerFree Image from public domain licenseJöns Jacob Berzelius. Stipple engraving by A. Tardieu after F. Krüger, 1828. https://www.rawpixel.com/image/13994854/jons-jacob-berzelius-stipple-engraving-tardieu-after-kruger-1828Free Image from public domain licenseJöns Jacob Berzelius. Lithograph by A. Farcy after F. Krüger. https://www.rawpixel.com/image/14009722/jons-jacob-berzelius-lithograph-farcy-after-krugerFree Image from public domain licenseHeinrich Friedrich Link. Stipple engraving by A. Tardieu after himself after F. Krüger. https://www.rawpixel.com/image/14010455/image-face-person-artFree Image from public domain licenseHet Russische leger (1800 - 1899) by Hilscher, Hilscher and Franz Krüger https://www.rawpixel.com/image/13768845/het-russische-leger-1800-1899-hilscher-hilscher-and-franz-krugerFree Image from public domain license