The bonds may be refunded in accordance with Article 6 (commencing with Section 16780) of Chapter 4 of Part 3 of Division 4 of Title 2, which is a part of the State General Obligation Bond Law. Approval by the electors of the state for the issuance of the bonds described in this title shall include approval of the issuance of any bonds issued to refund any bonds originally issued under this title or any previously issued refunding bonds.