Syafrita, Y., A. Istarini, M. Busra, S. Indra, and R. Susanti. “Relationship Between Plasma Level of Beta-Amyloid, Alpha-Synuclein, and Tau Protein With Cognitive Impairment in Parkinson Disease”. Open Access Macedonian Journal of Medical Sciences, vol. 10, no. B, Mar. 2022, pp. 663-7, doi:10.3889/oamjms.2022.7940.