CA Gov't Code Section 3544.5

A petition may be filed with the board, in accordance with its rules and regulations, requesting it to investigate and decide the question of whether employees have selected or wish to select an exclusive representative or to determine the appropriateness of a unit, by:

(a)

A public school employer alleging that it doubts the appropriateness of the claimed unit; or

(b)

An employee organization alleging that it has filed a request for recognition as an exclusive representative with a public school employer and that the request has been denied or has not been acted upon within 30 days after the filing of the request; or

(c)

An employee organization alleging that it has filed a competing claim of representation pursuant to subdivision (b) of Section 3544.1; or

(d)

An employee organization alleging that the employees in an appropriate unit no longer desire a particular employee organization as their exclusive representative, provided that such petition is supported by evidence of support such as notarized membership lists, cards, or petitions from 30 percent of the employees in the negotiating unit indicating support for another organization or lack of support for the incumbent exclusive representative. Such evidence of support shall be submitted to the board, and shall remain confidential and not be disclosed by the board. The board shall obtain from the employer the information necessary for it to carry out its responsibilities pursuant to this section and shall report to the employee organizations seeking recognition and to the public school employer as to the adequacy of the evidence of support.