The ENDOTRIAL study: a spontaneous, open-label, randomized, multicenter, crossover study on the efficacy of sildenafil, tadalafil, and vardenafil in the treatment of erectile dysfunction.
Jannini EA, Isidori AM, Gravina GL, Aversa A, Balercia G, Bocchio M, Boscaro M, Carani C, Corona G, Fabbri A, Foresta C, Forti G, Francavilla S, Granata AR, Maggi M, Mansani R, Palego P, Spera G, Vetri M, Lenzi A; Endotrial Study Group.
Jannini EA, et al.
J Sex Med. 2009 Sep;6(9):2547-60. doi: 10.1111/j.1743-6109.2009.01375.x. Epub 2009 Jun 29.
J Sex Med. 2009.
PMID: 19570039
Clinical Trial.