Be it further acted, That all bonds issued under this Act shall be sold on a basis of sealed proposals opened publicly by the city clerk at a time and place announced in a public notice published at least thirty (30) days in advance of such opening in the official city newspaper and in a publication carrying municipal bond notices and devoted primarily to financial news or to the subject of state and municipal bonds. The council by resolution shall determine which proposal shall be accepted or may reject all proposals and authorize the taking of new proposals.