契約原則 變更命令 採購契約要項 國際工程師協會 土木工程標準契約條款 紅皮書 美國建築師協會 工程變更 施工變更指示 二○○六年工程定作之採購與契約規範 重大變更原則 廢棄契約原則 Altering the content of an obligation to be based on contract Change orders Standard procurement contracts Federation internationale des ingenieurs-conseils FIDIC Conditions of contract for works of civil engineering construction Red book The American institute of architects Changes in the work Construction change directive German general terms of contract for works (VOB/B) 2006 Doctrine of cardinal change Doctrine of abandonment of contract