Sioux City Comm. Sch. v. Bd. of Public Inst. , 402 N.W.2d 739 ( 1987 )
Charles City Ed. Ass'n v. Public Emp. Rel. , 291 N.W.2d 663 ( 1980 )
Professional Staff Ass'n of Area Education Agency 12 v. Public Employment Relations Board , 373 N.W.2d 516 ( 1985 )