“ANALISIS STRATEGI DIFERENSIASI DALAM PELAYANAN BEAUTY SPA & SPA BABY TERHADAP KEUNGGULAN BERSAING DI RSIA ERIA BUNDA PEKANBARU”. Al Tamimi Kesmas: Jurnal Ilmu Kesehatan Masyarakat (Journal of Public Health Sciences), vol. 5, no. 2, November 2018, hlm. 25-34, https://jurnal.ikta.ac.id/kesmas/article/view/93.