Participants: Yuga Chŏngch'aek Yŏn'guso. [ ]; National Institute for Early Education Research (U.S.) [ ]; Yuga Chŏngchʻaek Kaebal Sentʻŏ (Korea) [ ]; Yuga Chŏngch'aek Yŏn'guso. [ TeilnehmendeR ]; National Institute for Early Education Research (U.S.) [ TeilnehmendeR ]; ...