Simadibrata, M., A. Rani, P. Adi, A. Djumhana, and M. Abdullah. “The Gastro-Esophageal Reflux Disease Questionnaire Using Indonesian Language: A Language Validation Survey”. Medical Journal of Indonesia, vol. 20, no. 2, May 2011, pp. 125-30, doi:10.13181/mji.v20i2.442.