Rockefeller Foundation records. Photographs. Series 100-1000 (FA003). Series 613: Korea; Sub series 613R: Korea-Humanities and Arts. Box 148. Folder 2840 Korean Language Society – Korean Dictionaries. RAC.
“The four scholars who labored over the Korean (HANGUL) Language Dictionary are pictured on Hangul Day, Ocrober 9, 1957, with the first six-volume publication. They are, left to right: CHUNG In-Seung, Kwon Seung-uk. Lee Kang-era, and YU chae-han.” – Caption on back of photograph