@article{oai:repository.dl.itc.u-tokyo.ac.jp:00039835, author = {Muramatu, Tosinobu}, issue = {3}, journal = {Journal of the Faculty of Science, the University of Tokyo. Sect. 1 A, Mathematics = 東京大学理学部紀要. 第1類A, 数学}, month = {Dec}, note = {application/pdf}, pages = {581--590}, title = {Products of fractional powers of operators(Dedicated to Professor Kosaku Yosida on his 60th birthday)}, volume = {17}, year = {1970} }