Conn. Gen. Stat. § 52-552k: Supplementary provisions.

Unless displaced by the provisions of sections 52-552a to 52-552l, inclusive, the principles of law and equity, including the law merchant and the law relating to principal and agent, estoppel, laches, fraud, misrepresentation, duress, coercion, mistake, insolvency or other validating or invalidating cause, supplement the provisions of said sections.