Oh and Huh teamed up to tell what happens. Their study is:
“What Happens When the Items of Examination and Correct Answer Is Opened in Medical School?” [article in Korean], D.J. Oh and S. Huh, Korean Journal of Medical Education, vol. 13, no. 1, May 2001, pp. 143-148. The authors are at Hallym University, Chunchon, Korea.