TY - JOUR AU - Achem, S R TI - Endoscopy-negative gastroesophageal reflux disease. The hypersensitive esophagus JO - Gastroenterol Clin North Am IS - 04 VL - 28 PY - 1999 DO - 10.1016/S0889-8553(05)70096-0 SP - 893 EP - 904, vii ER -