Norg, R. J., van de Beek, K., Portegijs, P. J., van Schayck, C. O., & Knottnerus, J. A. (2006). The effectiveness of a treatment protocol for male lower urinary tract symptoms in general practice: A practical randomised controlled trial. Oxford University Press.

Norg, Roelf JC, Kees van de Beek, Piet JM Portegijs, CP Onno van Schayck, và J André Knottnerus. The Effectiveness of a Treatment Protocol for Male Lower Urinary Tract Symptoms in General Practice: A Practical Randomised Controlled Trial. Oxford University Press, 2006.

Norg, Roelf JC, et al. The Effectiveness of a Treatment Protocol for Male Lower Urinary Tract Symptoms in General Practice: A Practical Randomised Controlled Trial. Oxford University Press, 2006.