(1) The term “district funding unit” or “district control unit” means:

  (a) The county in districts of the first and second class.

  (b) The city or the township in districts of the third class except as provided in subdivision (c).

  (c) The city or the incorporated village in districts of the third class in which portions of 2 townships comprise an incorporated village.

  (2) Except as otherwise provided in this act, a district funding unit shall be responsible for maintaining, financing, and operating the court only within its political subdivision. In districts of the third class a political subdivision shall not be responsible for the expenses of maintaining, financing, or operating the district court, traffic bureau, or small claims division incurred in any other political subdivision except as provided by section 8621 and other provisions of this act.

  (3) One or more district funding units within any district may agree among themselves to share any or all of the expenses of maintaining, financing, or operating the district court. To become effective such agreements must be approved by resolution adopted by the governing body of the respective political subdivisions entering into the agreement, and upon approval such agreements shall become effective and binding in accordance with, to the extent of, and for such period stated in that agreement.

  (4) The district funding unit shall supply such law books and legal reference resources as it deems necessary. No subsidy from state funds shall be required to stock any district court created by this act with law books or other legal reference works.