Robert M. Gimello, Peter N. Gregory, Studies in Chan and Hua-yen, Honolulu: University of Hawaii Press, 1983
Koh Seung-hak, “Chinul’s Hwaŏm Thought in the Hwaŏmnon chŏryo”, Acta Koreana Vol.17 No.1, Taegu, Korea: Academia Koreana, Keimyung University, 2014
Keel Hee-Sung, “Chinul: The Founder of the Korean Son Tradition”, Ph.D. Dissertation, Harvard University, 1977(published in Berkeley Buddhist Studies Series no.6, Berkeley: Institute of South and Southeast Asian Studies, 1984)