The legislative body may (a) provide for the construction or installation of any improvements authorized by Part 1 (commencing with Section 22000) of this division by proceedings taken pursuant to any other special assessment law or, in the case of a charter city, any procedural ordinance of the city and, (b) provide for the maintenance or servicing of those improvements by proceedings taken pursuant to Article 59 (commencing with Section 20890) of Chapter 1 of Part 3 of Division 2 of the Public Contract Code. The proceedings may be taken separately or combined. If combined, any of the several resolutions, reports, notices or other instruments provided for in Article 59 may be combined with those provided for in the other special assessment law or procedural ordinance.