Der Grundsatz der Verhältnismäßigkeit im Schuldvertragsrecht: zur Dogmatik ... - Michael Stürner - Google Books

http://books.google.de/books?id=FxAI_IIotZkC&pg=PA429&dq=billigkeit+und+ermessen&hl=de&sa=X&ei=BDQoUrCPN8nQtAbI14GgCw&ved=0CDwQ6

English summary: The principle of proportionality is a general legal principle which also applies to private law. On a comparative basis Michael Sturner analyses the structure of the proportionality principle and shows its significance for the law of…