@article{oai:u-ryukyu.repo.nii.ac.jp:02005314,
 author = {Kudaka, Shoju and Matsumoto, Shuichi and 松本, 修一},
 journal = {Ryukyu mathematical journal},
 month = {Dec},
 note = {紀要論文},
 pages = {11--20},
 title = {A quantum theoretical formulation of proper time for spin 1/2 particles},
 volume = {17},
 year = {2004}
}