S. Buulolo, E. Waruwu, H. Gulo, N. A. Buulolo, and F. Halawa, “The Effect of Service Leadership and Coworker Support on Employee Retention at Ulunoyo Community Health Center South Nias Regency”, ProBisnis , vol. 16, no. 5, pp. 1223–1229, Oct. 2025.