Useful reading material for understanding the balance of payments and
balance of payments equilibrium can be found in Chapter 2 of Michael
Melvin's book International Money and Finance which is
published by Addison-Wesley. Elementary discussions of the relationship
between changes in income and savings and investment and exports and
imports can be found in almost every basic principles of economics text.
An intermediate discussion can be found in Gregory Mankiw's
Macroeconomics intermediate textbook, which is published by
Worth Publishers. Simply consult the relevant indexes with regard to the
determinants of aggregate consumption and investment and exports and
imports.