Cal. RTC § 3702

(a) The tax collector shall publish the notice of intended sale once a week for three successive weeks in a newspaper of general circulation published in the county seat and in a newspaper of general circulation published in the public notice district in which the property is situated. If the same newspaper of general circulation is published in both the county seat and in the public notice district, or if the publication of the notice of sale is made in a newspaper which is determined pursuant to Section 3381 as most likely to afford adequate notice of the sale, a publication in that newspaper shall satisfy the requirements for publication set forth in this section. If there is no newspaper published in the county seat or in the public notice district, then publication in the location in which there is no newspaper may be made by posting notice in three public places in the county seat. The publication shall be started not less than 21 days prior to the date of the sale.

(b) For the purposes of this section, publication of notice in a public notice district is governed by Chapter 1.1 (commencing with Section 6080) of Division 7 of Title 1 of the Government Code.