TY - JOUR AU - Goo Ishikawa AU - Yoshinori Machida, AU - Masatomo Takahashi TI - Geometry of D_4 conformal triality and singularities of tangent surfaces JO - Journal of Singularities PY - 2015 SP - 27 EP - 52 VL - 12 PB - mathdoc UR - http://geodesic.mathdoc.fr/articles/10.5427/jsing.2015.12c/ DO - 10.5427/jsing.2015.12c ID - 10_5427_jsing_2015_12c ER -