http://www.family.co.jp/goods/otona/otonanooyatu/hc0g7400000gf4wb.html http://ameblo.jp/kiki3nyanco/day-20120220.html

http://gihyo.jp/dev/serial/01/modern-perl/0015 http://search.cpan.org/~msergeant/Time-Piece-1.20/Piece.pm