Immanuel Edy Suranta Sebayang. “Analysis of the Promotion Mix Strategy on the Number of Martabe Savings Customers at PT Bank Sumut, Tembung Branch Office”. Jurnal Indonesia : Manajemen Informatika Dan Komunikasi, Vol. 5, no. 3, June 2024, pp. 2216-27, doi:10.35870/jimik.v5i3.866.