RT Journal Article SR Electronic T1 Polarity JF Canadian Family Physician JO Can Fam Physician FD The College of Family Physicians of Canada SP e90 OP e90 DO 10.46747/cfp.6703e90 VO 67 IS 3 A1 Yelena Zavalishina YR 2021 UL http://www.cfp.ca/content/67/3/e90.abstract AB