Nonmotoric Symptoms Scale (NMSS) Validity and Reliability Test in Patients with Parkinson's Disease in Dr. Soetomo General Hospital, Surabaya, Indonesia: A Questioner Validation Study, Hamdan, Muhammad, Nugraha Priya, Librata Pramitha Nayana, and Cecilia Cindy , Pharmacognosy Journal, June 2023, Volume 15, Issue 3, p.316-320, (2023)