TY  - BOOK
AU  - Thomas, Joseph Miller,
TI  - Differential systems
U1  - Q 517.38 THO 
PY  - 1937///
CY  - New York
PB  - N. Y.,  American Mathematical Society
KW  - Differential equations, Partial
KW  - Pfaff's problem
N1  - Includes bibliographical references
ER  -