Bolangitan, Asna Heti, and Sendy Ceria Pasaribu. 2023. “Improvements in Tutor Efficiency at Non-Profit TOMOHON Community Learning Centres As a Function of Management and Leadership Style”. EUROPEAN JOURNAL OF BUSINESS STARTUPS AND OPEN SOCIETY 3 (5):37-43. http://inovatus.es/index.php/ejbsos/article/view/1655.