http://www.gengokk.co.jp/thesaurus/

http://www2u.biglobe.ne.jp/~butasan/

http://www.informatik.uni-ulm.de/ni/mitarbeiter/HKestler/vennm/

http://www.intellimark.co.jp/kotakukobo/1.html

http://www.optics.co.jp/frereboard.html

http://www.readwritethink.org/materials/venn/

http://www.teach-nology.com/web_tools/graphic_org/venn_diagrams/

http://www.asahi-net.or.jp/~zm5s-nkmr/

http://www.asakusakid.com/diary/stream_corumn.html

http://sa_yoshi.at.infoseek.co.jp/ocha/review-kakikata.html