The bonds may be sold at no less than par less a discount of not to exceed 5 percent, at public sale held after notice published once at least five days prior to the sale in a newspaper of general circulation published in the community, or, if there is none, in a newspaper of general circulation published in the county. The bonds may be sold at not less than par to the federal government at private sale without any advertisement.

The amendment to this section made at the 1969 Regular Session of the Legislature shall be applicable to bonds of a redevelopment agency which have been authorized by the agency prior to the effective date

of the amendment but which have not been issued prior to such date.