Yashikor References Asahi Camera editorial staff. Shōwa 10–40nen kōkoku ni miru kokusan kamera no rekishi (昭和10〜40年広告にみる国産カメラの歴史, Japanese camera history as seen in advertisements, 1935–1965). Tokyo: Asahi Shinbunsha, 1994. . External links Comprehensive Pentax Screwmount (M42) Lens info User reviews of Takumar lenses at Pentaxforums.com Photographic lenses by brand Pentax lenses Japanese brands Japanese inventions