Oklahoma constitution
Article XIII: education
Section 6

The Legislature shall provide for a system of textbooks for the common schools of the State, and the State through appropriate legislation shall furnish such textbooks free of cost for use by all pupils therein. The Legislature shall authorize the Governor to appoint a committee composed of active educators of the State, whose duty it shall be to prepare official multiple textbook lists from which textbooks for use in such schools shall be selected by committees composed of active educators in the local school districts in a manner to be designated by the Legislature.