K.K. Ataka Shōkai (安宅商会) was a Japanese distributor active in the late 1930s and early 1940s. From 1939, it invested money into Takachiho, predecessor of Olympus, and partly took control of the company. Its Tokyo branch became the distributor of the Olympus Six and Super Olympus cameras until the end of the war; the address was Marunouchi Yaesu Building (丸ノ内八重洲ビル).
- Advertisements dated June 1940, December 1940 and April 1941 reproduced in Hibi, p.63 of Kurashikku Kamera Senka no.8, mentioning the "machinery department" (機械部) of the "Tokyo branch" (東京支店) of Ataka. The June and December 1940 advertisements are also reproduced in Kokusan kamera no rekishi, pp.62–3. Advertisement dated 1942 or later, reproduced in Nostalgic Camera by Toshio Inamura. Advertisement on p.4 of Nihon Shashin Kōgyō Tsūshin, February 15, 1944, reproduced on p.68 of Hyaku-gō goto jūkai no kiroku.
- Asahi Camera (アサヒカメラ) 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. ISBN 4-02-330312-7.
- Hibi Takashi (日比孝). "Nihon no supuringu kamera: Orinpasu" (日本のスプリングカメラ・オリンパス, "Japanese folding cameras: Olympus"). Kamera Rebyū: Kurashikku Kamera Senka (カメラレビュー クラシックカメラ専科) / Camera Review: All about Historical Cameras no.8, September 1986. No ISBN number. Supuringu kamera (スプリングカメラ, special issue on spring cameras). Pp.62–5.
- Sakai Shūichi (酒井修一). "Orinpasu no rekishi" (オリンパスの歴史, "History of Olympus"). Kamera Rebyū: Kurashikku Kamera Senka (カメラレビュー クラシックカメラ専科) / Camera Review: All about Historical Cameras no. 20, 25 March 1992. No ISBN number. Orinpasu no subete (オリンパスのすべて, special issue on Olympus). Pp.6–9.