RT Journal Article SR Electronic T1 Systematic review of Viagra RCTs. JF British Journal of General Practice JO Br J Gen Pract FD British Journal of General Practice SP 329 OP 329 VO 52 IS 477 A1 Blanker, Marco H A1 Thomas, Siep A1 Bohnen, Arthur M YR 2002 UL http://bjgp.org/content/52/477/329.1.abstract AB