Hiroichi Sugawara

1936

• Chōkaku shōgaiji no gengo jōhō nyūryoku keiro to jōhō shori kinō no kankei ni kansuru kenkyū
• Chōkaku shōgaiji no gengo kyōiku ni okeru shushihō no katsuyō to shakai tekiō no kenkyū
• Shinshin shōgaiji no shakai seikatsu to shigen no riyō