(a) An authority shall have power to issue bonds from time to time in its discretion for any of its corporate purposes including the payment of principal and interest upon any advances for surveys and plans for redevelopment projects. An authority shall also have power to issue refunding bonds for the purpose of paying or retiring or in exchange for bonds previously issued by it. An authority may issue such types of bonds as it may determine, including (without limiting the generality of the foregoing) bonds on which the principal and interest are payable: (1) Exclusively from the income, proceeds and revenues of the redevelopment project financed with the proceeds of such bonds; or(2) Exclusively from the income, proceeds and revenues of any of its redevelopment projects whether or not they are financed in whole or in part with the proceeds of such bonds: Provided, That any such bonds may be additionally secured by a pledge of any loan, grant or contributions, or parts thereof, from the federal government or other sources, or a mortgage of any redevelopment project or projects of the authority.(b) Neither the commissioners of an authority nor any person executing the bonds shall be liable personally on the bonds by reason of the issuance thereof. The bonds and other obligations of the authority (and such bonds and obligations shall so state on their face) shall not be a debt of the municipality, the county or the state and neither the municipality, the county nor the state shall be liable thereon, nor in any event shall such bonds or obligations be payable out of any funds or properties other than those of said authority acquired for the purposes of this article. The bonds shall not constitute an indebtedness within the meaning of any constitutional or statutory debt limitation or restriction. Bonds of an authority are declared to be issued for an essential public and governmental purpose and to be public instrumentalities and, together with interest thereon and income therefrom, shall be exempt from all taxes. Such bonds need not be offered by the authority to the state sinking fund commission at any time and an authority shall not be required to turn over any surplus or sinking funds to the state sinking fund commission.(c) Bonds of an authority shall be authorized by its resolution and may be issued in one or more series and shall bear such date or dates, be payable upon demand or mature at such time or times, bear interest at such rate or rates, not exceeding twelve per centum per annum, be in such denomination or denominations, be in such form either coupon or registered, carry such conversion or registration privileges, have such rank or priority, be executed in such manner, be payable in such medium of payment, at such place or places, and be subject to such terms of redemption (with or without premium) as such resolution, its trust indenture or mortgage may provide.(d) The bonds shall be sold at not less than par at public sale held after notice published as a Class I legal advertisement in compliance with the provisions of article three, chapter fifty-nine of this code, and the publication area for such publication shall be the area of operation. Such publication shall be made at least ten days prior to such sale. The notice may be published in such other medium of publication as the authority may determine: Provided, That such bonds may be sold to the federal government at private sale at not less than par, and, in the event less than all of the bonds authorized in connection with any project or projects are sold to the federal government, the balance of such bonds may be sold at private sale at not less than par at an interest cost to the authority of not to exceed the interest cost to the authority of the portion of the bonds sold to the federal government.(e) In case any of the commissioners or officers of the authority whose signatures appear on any bonds or coupons shall cease to be such commissioners or officers before the delivery of such bonds, such signatures shall, nevertheless, be valid andsufficient for all purposes, the same as if such commissioners or officers had remained in office until such delivery. Any provision of any law to the contrary notwithstanding, any bonds issued pursuant to this article shall be fully negotiable.(f) In any suit, action or proceedings involving the validity or enforceability of any bond of an authority or the security therefor, any such bond reciting in substance that it has been issued by the authority to aid in financing a redevelopment project, as herein defined, shall be conclusively deemed to have been issued for such purpose and such project shall be conclusively deemed to have been planned, located and carried out in accordance with the purposes and provisions of this article.