TY - JOUR AU - Kishi, Haruo TI - Contingency and Existence T2 - Journal of Tezukayama Jr. College. Natural science SN - 02865092 PY - 1982 DA - 1982/03/00 VL - 19 SP - 33-57 UR - http://ci.nii.ac.jp/naid/110001022099/en/ ER -