Hallinger, P.(1992).The evolving role of American principals: From managerial to instructional to transformational leaders.Journal of Educational Administration.30(3),35-48.
Krug, F. S.(1996).The relationship between the instructional management behavior of elementary school principal and student achievement.University of San Francisco.
Sherpara, L. B.(1993).A study of the relationship among instructional leadership behaviors of the school principal and selected school-level characteristics.University of Ottawa, Canada..