29 U.S.C. § 2105: Procedures in addition to other rights of employees

The rights and remedies provided to employees by this chapter are in addition to, and not in lieu of, any other contractual or statutory rights and remedies of the employees, and are not intended to alter or affect such rights and remedies, except that the period of notification required by this chapter shall run concurrently with any period of notification required by contract or by any other statute.