@article{oai:ir.kagoshima-u.ac.jp:00001747,
 author = {SUENAGA, Katsuyuki and SAKAI, Manabu},
 journal = {鹿児島大学理学部紀要, Reports of the Faculty of Science, Kagoshima University},
 month = {Dec},
 pages = {47--54},
 title = {How to join two circles with one circle inside the other},
 volume = {33},
 year = {2000}
}