Whurr, R. and Lorch, Marjorie and Lindsay, M. and Brookes, G.B. and Marsden, C.D. and Jahanshahi, M. (1998) Psychological function in spasmodic dysphonia before and after treatment with Botulinum Toxin. Journal of Medical Speech - Language Pathology 6 (2), pp. 81-92. ISSN 1065-1438.