A Biofeedback App to Instruct Abdominal Breathing (Breathing-Mentor): Pilot Experiment.
JMIR Mhealth Uhealth. 2019 Sep 30;7(9):e13703. doi: 10.2196/13703.
JMIR Mhealth Uhealth. 2019.
PMID: 31573919
Free PMC article.