Hussain, I., Brady, C., Swinn, M., Mathias, C., & Fowler, C. (2001). Treatment of erectile dysfunction with sildenafil citrate (Viagra) in parkinsonism due to Parkinson's disease or multiple system atrophy with observations on orthostatic hypotension. BMJ Group.

Hussain, I., C. Brady, M. Swinn, C. Mathias, ja C. Fowler. Treatment of Erectile Dysfunction With Sildenafil Citrate (Viagra) in Parkinsonism Due to Parkinson's Disease or Multiple System atrophy With Observations On Orthostatic Hypotension. BMJ Group, 2001.

Hussain, I., et al. Treatment of Erectile Dysfunction With Sildenafil Citrate (Viagra) in Parkinsonism Due to Parkinson's Disease or Multiple System atrophy With Observations On Orthostatic Hypotension. BMJ Group, 2001.