Any plan or system adopted pursuant to the provisions of this article shall be based either on the purchase of an insured group plan of retirement annuities funded through a group carrier or on a noninsured trust retirement plan; or such plan or system may provide for participation in the public employees' retirement association as provided in article 51 of this title.
Source: L. 87: Entire article added, p. 1087, � 2, effective July 1.