@en|Scanning of a March 1930 [[Parker]] advertising for the [[Duofold]] model and its ''conversion'' to a desk pen. Published on ''The National Geographic'', Vol. LVII, No. 3. Retouched by the author for a better sharpness. | @en|Scanning of a March 1930 [[Parker]] advertising for the [[Duofold]] model and its ''conversion'' to a desk pen. Published on ''The National Geographic'', Vol. LVII, No. 3. Retouched by the author for a better sharpness. |