Chapter 17
Theory and solutions of Ordinary Differential equations, Donald Greenspan, 1960

17.1 Chapter 2. First order equations. Exercises at page 14
17.2 Chapter 3. Linear differential equations of second order. Exercises at page 31
17.3 Chapter 4. The general linear differential equation of order n. Exercises at page 63
17.4 Chapter 6. Linear systems. Exercises at page 110
17.5 Chapter 7. Special functions. Exercises at page 124