• publisher: New York city, Teachers college, Columbia university
  • creator: Arai, Tsuru, 1887-
  • Keyword: Mental fatigue.
  • years: 1912.
  • pages: 2 p.l., 115 p.
  • class: QP421
  • notes: Also published as thesis (PH. D.) Columbia university, 1912.
  • download: pdf file