“Spring Bed Business As a Livelihood for the People of Sei Semayang Village, Sunggal District, Deli Serdang Regency”. JISIP (Jurnal Ilmu Sosial dan Pendidikan) 8, no. 1 (January 2, 2024): 227–241. Accessed June 16, 2026. https://ejournal.mandalanursa.org/index.php/JISIP/article/view/6113.