Virtual reality-based emotion-to-emotion therapy for post-traumatic stress disorder: Protocol for a randomized controlled trial of efficacy, safety, and cost-effectiveness - Do-Eun Lee; Namju Lee; Nam-Kwen Kim; Joohee Seo; Jaeuk U. Kim; In Chul Jung; Moon Joo Cheong; Hyung Won Kang (PLOS One, 2026)