Muljadi, C., L. Idawati, and A. Ardi. “Developing Leadership Skills in Administrative Staff Through Professional Development Program at School Pelita Harapan”. JIIP - Jurnal Ilmiah Ilmu Pendidikan, vol. 5, no. 7, July 2022, pp. 2547-53, doi:10.54371/jiip.v5i7.723.