"Research notes of Ippei Wakabayashi" "Archived copy"(PDF). Archived from the original(PDF) on 2011-06-13. Retrieved 2011-03-31.{{cite web}}: CS1 maint: archived copy as title (link)
"Research notes of Ippei Wakabayashi" "Archived copy"(PDF). Archived from the original(PDF) on 2011-06-13. Retrieved 2011-03-31.{{cite web}}: CS1 maint: archived copy as title (link)