• Martindale, The Extra Pharmacopoeia, 32nd edn., Pharmaceutical Press, 1999, 1629
• Terrett, N.K. et al., Bioorg. Med. Chem. Lett., 1996, 6, 1819-1824, (sildenafil citrate)
• Eur. Pat., 1992, Pfizer, 463 756; CA, 116, 255626q, (synth, pharmacol)
• Martel, A.M. et al., Drugs of the Future, 1997, 22, 138-143, (synth, pharmacol)
• Chuang, A.T. et al., J. Urol. (Baltimore), 1998, 160, 257-261, (pharmacol)
• Palmer, E., Chem. Br., 1999, 24-26, (rev)
• Cooper, J.D.H. et al., J. Chromatogr., B: Biomed. Appl., 1997, 701, 87-95, (hplc)
• Ballard, S.A. et al., J. Urol. (Baltimore), 1998, 159, 2164-2171; 160, 242-246, (pharmacol)
• Noss, M.B. et al., Drugs of Today (Barcelona), 1999, 35, 211-217
• Dale, D.J. et al., Org. Process Res. Dev., 2000, 4, 17-22, (synth)
• Cheitlin, M.D. et al., Circulation, 1999, 99, 168-177
• Boolell, M. et al., Br. J. Urol., 1996, 78, 257-261, (pharmacol)
• Morales, A. et al., Int. J. Impot. Res., 1998, 10, 69-74, (use)
• Langtry, H.D. et al., Drugs, 1999, 57, 967-989