TY - `BOOK` AU - Yang, Deane TI - Involutive hyperbolic differential systems PB - American Mathematical Society CY - Providence, RI PY - 1987 LA - eng SE - XI, 93 S. T2 - Memoirs of the American Mathematical Society M1 - 370 SN - 0-8218-2433-3 SN - 978-0-8218-2433-7 CN - 88 W 29 AN - UBHD-3501369 ER -