@article{oai:ir.kagoshima-u.ac.jp:00001772,
 author = {KAWAI, Toru and 河合, 徹},
 journal = {鹿児島大学理学部紀要. 数学・物理学・化学, Reports of the Faculty of Science, Kagoshima University. Mathematics, physics, chemistry},
 month = {Dec},
 pages = {45--48},
 title = {AN ELEMENTARY AXIOM SYSTEM OF NONSTANDARD SET THEORY},
 volume = {21},
 year = {1988}
}