For the purpose of refunding any bonds issued under the provisions of Section 37-29-109, including refunding bonds, any board of trustees may make and issue refunding bonds in such amount as may be necessary to pay off and redeem the bonds to be refunded together with unpaid and past due interest thereon and any premium which may be due under the terms of such outstanding bonds, together also with the cost of issuing such refunding bonds. Said board may sell the same in like manner as provided for the initial issuance of bonds. With the proceeds of any such refunding bonds such board shall pay off, redeem and cancel such old bonds and interest coupons as may have matured, or such bonds as may have been called for payment and redemption together with the past due interest and premium, if any, due thereon; such bonds may be issued and delivered in exchange for a like par value amount of bonds to refund which the refunding bonds were issued. No refunding bonds issued hereunder shall be payable in more than twenty-five (25) years from the date thereof, nor shall any such refunding bonds bear interest at a rate in excess of that allowed in Section 75-17-101, Mississippi Code of 1972, payable semiannually. All such refunding bonds shall be payable from the same source or sources as were pledged to the payment of the bonds refunded thereby and, in the discretion of such board of trustees, may be payable from any other source or sources which may be pledged to the payment of revenue bonds issued hereunder. Bonds of two (2) or more outstanding issues of the same board may be refunded in a single issue of refunding bonds.