About OSAWA YOSHINORI
About KIMOTO JUN'ICHI
About 郡是高分子工業
About SAEKI KINGO
About 東京都 下水道局
About KAWAI TADASHI
About 日本大 生産工
About 下水道協会誌
About sewerage
About flexuosity
About Sewerage,sewers attached facilities
About Piping design and work
About 可とう性
About 下水道管
About 接続構造
About 基礎
About 研究