Assume CA Codes apply:

Per http://law.justia.com/california/codes/2009/corp/600-605.html

Section 600

" (d) Special meetings of the shareholders may be called by the
board, the chairperson of the board, the president, the holders of
shares entitled to cast not less than 10 percent of the votes at the
meeting, or any additional persons as may be provided in the articles
or bylaws."