Available material:
1900-1x-Koh-I-Noor-Hardtmuth
1901-1x-Koh-I-Noor-Hardtmuth
1902-0x-Koh-I-Noor-Hardtmuth
1902-1x-Koh-I-Noor-Hardtmuth
1903-1x-Koh-I-Noor-Hardtmuth
1906-12-Hardtmuth
1908-04-Waterman-1x-Sdraio
1911-10-Koh-I-Noor-Hardtmuth
1911-11-Koh-I-Noor-Hardtmuth
1911-12-Koh-I-Noor-Hardtmuth
1911-1x-Koh-I-Noor-Hardtmuth
1912-09-Koh-I-Noor-Hardtmuth
1912-10-Koh-I-Noor-Hardtmuth
1913-1x-Koh-I-Noor-Hardtmuth
1914-GuidaMilanoSavallo-WatermanSoennecken
191x-Hardtmuth-Pencils-Front
191x-Hardtmuth-Pencils-Retro
1922-08-Papierhandler-Hardtmuth-EtAl
1928-11-Hardtmuth-Nibs
1932-04-Papierhandler-Hardtmuth-KohINoor
1932-05-Papierhandler-Kaweco-EtAl
1936-Hardtmuth-KohINoor
1937-Hardtmuth-ErasersGum
1938-06-Catalogo-Vagnino-p112
1941-Hardtmuth-Mephisto
Hardtmuth-Airless-LinedBrown-Back
Hardtmuth-Airless-LinedBrown-Cap
Hardtmuth-Airless-LinedBrown-CapSide
Hardtmuth-Airless-LinedBrown-Capped
Hardtmuth-Airless-LinedBrown-Closed
Hardtmuth-Airless-LinedBrown-Front
Hardtmuth-Airless-LinedBrown-Fronte
Hardtmuth-Airless-LinedBrown-Head
Hardtmuth-Airless-LinedBrown-Inscr
Hardtmuth-Airless-LinedBrown-Nib
Hardtmuth-Airless-LinedBrown-NibSide
Hardtmuth-Airless-LinedBrown-Open
Hardtmuth-Airless-LinedBrown-Posed
Hardtmuth-Airless-LinedBrown-Section
Hardtmuth-Airless-LinedBrown-View
1914-Whitaker-RedBook-WhoIsWho-Hardtmuth
1933-AnnuarioGenerale-Italia-p1070