Stephen Swann & Christian von Bar 
Unjustified Enrichment [PDF ebook] 
(PEL Unj. Enr.)

‚Unjustified enrichment‘ is one of the three main non-contractual obligations dealt with in the DCFR.
In recent years unjustified enrichment has been one of the most intellectually animated areas of private law. In an area of law whose territory is still partially uncharted and whose boundaries are contested, this volume of Principles of European Law will be invaluable for academic analysis of the law and its development by the courts.
During the drafting process, comparative material from over 25 different EU jurisdictions has been taken into account. The work therefore is not only a presentation of a future model for European rules to come but provides also a fairly detailed indication of the present legal situation in the Member States.