AIDIL PUTRA; BUDIANTO; FREE ANTONIUS SIMANJUNTAK. IMPROVING BUSINESS COMMUNICATION AND NEGOTIATION SKILLS TO BUILD SELF-CONFIDENCE IN CHILDREN AT THE BENIH KEBAKAN POLONIA MEDAN ORPHANAGE. Journal of Community Service, [S. l.], v. 3, n. 2, p. 12–22, 2026. Disponível em: https://journal.trasaka.com/index.php/JCoS/article/view/100. Acesso em: 21 jul. 2026.