Each lease agreement, note, mortgage, or other instrument evidencing the obligations of a project sponsor shall provide that the rents or principal, interest, and other charges payable by the project sponsor shall be sufficient at all times, (a) to pay the principal of, sinking fund payments, if any, the premium, if any, and the interest on outstanding bonds issued in respect of such project as the same shall become due and payable, (b) to create and maintain reserves which may, but need not, be required or provided for in the resolution relating to the bonds, and (c) to pay its share of the administrative costs and expenses of the authority. The issuer shall pledge the revenues derived, and to be derived, from a project or from a project sponsor for

the purposes specified in (a), (b), and (c) of the preceding sentence and additional bonds may be issued which may rank on a parity with other bonds relating to the project to the extent and on the terms and conditions provided in the bond resolution.