Purba, Sopianna Br. 2018. “The Effect of Work Conflict on Teacher Performance in Sinar Harapan Education Foundation. Beringin Deli Serdang Regency”. Enrichment : Journal of Management 9 (1, Novembe), 1-3. https://doi.org/10.35335/enrichment.v9i1, Novembe.6.