Elfrida Yuliana Simamora, Mauly Purba, Pulumun P. Ginting, and Junita Batubara, “DIVERSITY OF MUSIC GENRES IN SUNDAY SERVICES OF HKBP CHURCH IN MEDAN CITY: THEOLOGICAL, CULTURAL, AND MUSIC MANAGEMENT PERSPECTIVES”, IJSET, vol. 5, no. 2, pp. 1611–1618, Jan. 2026.