Iwai, M., S. Koyama, K. Takeda, Y. Hirakawa, I. Motoya, H. Sakurai, Y. Kanada, Y. Okada, N. Kawamura, M. Kawamura, and S. Tanabe. “Effect of Lee Silverman Voice Treatment® BIG on the Major Motor Symptoms in Patients With Moderate Parkinson’s Disease: An Observational Study”. JOURNAL OF GERONTOLOGY AND GERIATRICS, Vol. 72, no. 2, May 2024, pp. 76-82, doi:10.36150/2499-6564-N711.