RT Journal Article SR Electronic T1 Combined pH-impedance testing for reflux: current state of play and future challenges JF Frontline Gastroenterology JO Frontline Gastroenterol FD BMJ Publishing Group Ltd SP 154 OP 155 DO 10.1136/flgastro-2017-100840 VO 8 IS 3 A1 Santosh Sanagapalli A1 Rami Sweis YR 2017 UL http://fg.bmj.com/content/8/3/154.abstract AB