Pourhoseingholi, M. A., Faghihzadeh, S., Habibi, M., Safaee, A., Qafarnejad, F., Rostami Nejad, M., Moghimi Dehkordi, B. and Zali, M. R. (2009) “Association between duration of heartburn and patient characteristics: a quantile regression analysis”, Gastroenterology and Hepatology from Bed to Bench, 1(2). doi: 10.22037/ghfbb.v1i2.22.