Already own some of these titles? You can still get package savings by making substitutions! You may make a “one for one” substitution with any book that we offer of equal or lesser value to the book(s) you already own, and still receive the package discount. In this package, you can make up to 2 substitutions.

Here is how: Simply add the package that contains the book(s) you already own to your shopping cart, then enter the title you wish to substitute in the “Order Notes” box at checkout. It’s that easy!