Kyung-ann Lee, Seung-hwan Jung, Jong-sun Kim, and Hyun-sook Kim. “Comparison of the Efficacy and Safety of Oligomeric Proanthocyanidins and Nifedipine in Patients With Primary Raynaud’s Phenomenon: An Open-Label, Randomized, Prospective Pilot Study”. Archives of Rheumatology 38, no. 3 (September 30, 2023): 477–479. Accessed October 3, 2025. http://anadolupsikiyatri.net/index.php/pub/article/view/1364.