How do I ask PERB to establish a "bargaining unit"?

A bargaining unit will be established by PERB as a result of a petition filed by a
public employee, public employer, or employee organization.  A public hearing to receive
evidence concerning the makeup of an appropriate unit will be held by PERB unless the
petitioner and public employer agree to the composition of the unit, PERB tentatively
approves the agreement and no objections to that agreement are filed with PERB after notice
of the tentative approval is publicized.