1. Department of ENT-HNS, Faculty of Medicine, Andalas University, West Sumatra, Indonesia – Dr. M. Djamil General Hospital Padang, West Sumatra, Indonesia
2. Department of ENT-HNS, Faculty of Medicine, Andalas University, West Sumatra, Indonesia – Biomedical Laboratory of Dr. M. Djamil General Hospital Padang, West Sumatra, Indonesia, Faculty of Medicine, Andalas University, West Sumatra, Indonesia
3. Biomedical Laboratory, Faculty of Medicine, Andalas University, West Sumatra, Indonesia