Every ordinance or resolution passed by the council shall be signed by the mayor or by two council members, attested by the city clerk or city administrator and filed and preserved by him/her. Every ordinance shall be published at least once in the official newspaper. Resolutions may be published by order of the council. To the extent and in the manner provided by law an ordinance may incorporate by reference a statute of Minnesota, a state administrative rule or a regulation, a code, or ordinance or part thereof without publishing the material referred to in full.