TY - JOUR AU - Masaaki Yoshida AU - Takeshi Sasaki TI - Linear differential Equations in Two Variables of Rank Four. I. JO - Mathematische Annalen PY - 1988 SP - 69 EP - 94 VL - 282 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MAN_1988__282_2_164450/ ID - MAN_1988__282_2_164450 ER -