William Koller

International multicenter pilot study of the first comprehensive self‐completed nonmotor symptoms questionnaire for Parkinson's disease: The NMSQuest study

Paolo Barone, Graeme MacPhee, Fabrizio Stocchi, 2006, Movement disorders : official journal of the Movement Disorder Society.

Lack of association between essential tremor and Parkinson's disease

W. Koller, L. Findley, William Koller, 1988, Annals of neurology.

Treatment interventions for Parkinson's disease: an evidence based assessment

Werner Poewe, Cristina Sampaio, Olivier Rascol, 2002, The Lancet.