RT Journal Article SR Electronic T1 Sildenafil - from POM to P JF Drug and Therapeutics Bulletin JO Drug Ther Bull FD BMJ Publishing Group Ltd SP 123 OP 125 DO 10.1136/dtb.2018.10.000024 VO 56 IS 10 YR 2018 UL http://dtb.bmj.com/content/56/10/123.abstract AB