“Probiotic Supplements For Depression In Parkinson’s Disease (Pro-Park): A Randomized, Triple-Blind, Placebo-Controlled, Phase IIb Trial Protocol”. Principles and Practice of Clinical Research 10, no. 2 (August 3, 2024). Accessed October 4, 2024. https://journal.ppcr.org/index.php/ppcrjournal/article/view/316.