Tōkei Iinkai. Jimukyoku

• Shōwa Nijūgonen kokusei chōsayō shokugyō bunrui to Shōwa jūgonen kokusei chōa shokumei hyō ; 1950 nen Beikoku jinkō sensasu shokugyō bunrui ; Kokusai hyōjun shokugyō bunrui hikakuhyō