Sitepu IL, Rohani L. The Role of Group Communication in Volunteer Self-Concept at Sikkola Rakyat Kota Medan. J-IbM [Internet]. 2026 Jun. 12 [cited 2026 Jun. 16];6(1):70-5. Available from: https://journal.aira.or.id/j-ibm/article/view/1690