For the purpose of paying the cost of such offstreet parking facility, or any portion thereof or to refund all or a portion of any outstanding bonds of the city authorized to be refunded by sections 19-3301 to 19-3326, the mayor and city council shall have power and may, by ordinance, cause to be issued general obligation bonds of the city, to be called Offstreet Parking Bonds of the City of ......., Nebraska, payable in not exceeding twenty years from date and bearing interest, payable either annually or semiannually, not exceeding a rate of twelve percent per annum with interest coupons attached. In such cases they shall also provide that special taxes levied within the district pursuant to section 19-3315 shall constitute a sinking fund for the payment of such bonds and the mayor and city council may, in the ordinance, pledge all or any part of the revenue from fees and charges on the use of the parking facility or fees and charges from onstreet parking meters within the district not already pledged as security for such bonds. There shall be levied upon all the taxable property in such city a tax which, together with such sinking fund derived from special assessments and other revenue pledged for the payment of the bonds and interest thereon, shall be sufficient to meet payments of interest and principal as the same become due. All such bonds shall bear such date or dates, mature at such time or times, be in such denominations, be in such form either coupon or registered, carry such registration privileges, be executed in such manner, be payable in such medium of payment, and at such place or places within or without the State of Nebraska as such ordinance may provide. No proceedings for the issuance of bonds of any city shall be required other than those required by the provisions of sections 19-3301 to 19-3326. Such bonds may be issued either before or after the completion of the acquisition or construction of the offstreet parking facility, as the mayor and city council may determine best. For the purpose of paying costs of an offstreet parking facility prior to issuance of bonds, warrants may be issued by the mayor and city council upon such terms as the mayor and city council may determine, which warrants shall be redeemed and paid upon the sale of bonds authorized in this section.