by 양송희(Song Hee Yang), 이현주(Hyun Ju Lee), 박성지(Sung Ji Park)
Published in 언어치료연구 (2020)

by 현혜선(Hye Son Hyeon), 김숙령(Sook Ryong Kim)
Published in Korean Journal of child studies (2007)

by 박선희(Sun-Hee Park)
Published in 언어치료연구 (2005)