Michael Fredrik Sihombing; Immanuel Onasis Kha Napitupulu; Ferry Deni Doloksaribu; Yesica Febrianti Tambunan; Pinka Laura Malau; Ropinus Sidabutar. Transformational Leadership Model of School Principals in Strengthening Civic Values: A Case Study at Erlangga Senior High School. YJSSH 2025, 1, 193-202.