大陆法系不当得利制度起源于罗马法，经法国民法继承发展，至德国民法典和瑞士债务法，其基本理论体系已趋完善；
Unjust enrichment in civil-law system , whose basic theory has almost consummated , originated in Roman law and was inherited and developed in French civil law and German civil code and Swiss debt law .
瑞士债务法