Theory Of Differential Equations. Six Volumes Bound As Three. Vol. 1: Exact Equations And Pfaff's Problem; Vol. 2: Ordinary Equations, Not Linear; Vol 3: Ordinary Equations, Not Linear; Vol 4: Ordinary Linear Equation; Vol 5 & 6: Partial Differential Equations

Theory Of Differential Equations. Six Volumes Bound As Three. Vol. 1: Exact Equations And Pfaff's Problem; Vol. 2: Ordinary Equations, Not Linear; Vol 3: Ordinary Equations, Not Linear; Vol 4: Ordinary Linear Equation; Vol 5 & 6: Partial Differential Equations - Andrew Russell Forsyth