(a) The net bonded indebtedness incurred for all public purposes shall not at any time exceed the maximum amount permitted by law, provided that in computing such bonded indebtedness there shall be excluded money borrowed on special assessment bonds, even though they are a general obligation of the city, mortgage bonds, revenue bonds, bonds in anticipation of state-returned revenues to the extent permitted by law, and any other bonds or indebtedness excluded by law from such limitation. The amount of funds accumulated for the retirement of any outstanding bonds shall also be deducted from the amount of bonded indebtedness.
(b) No bonds shall be sold to obtain funds for any purpose other than that for which they were specifically authorized, and if such bonds are not sold within the time limited by law, such authorization shall be null and void.
(c) The issuance of any bonds not requiring the approval of the electorate shall be subject to applicable requirements of law with reference to public notice in advance of authorization of such issues, filing of petitions for a referendum on such issuance, holding such referendum, and other applicable procedural requirements.