Open the book to the middle and slide the opened book into a large plastic zip-locking bag.
Crumple three to four pieces of newspaper and place them in the zip bag with the opened book along with one fabric softener sheet. Seal the plastic bag and allow the newspaper and dryer sheet to work at neutralizing the mold smell in the book. Open the zip bag after one day to assess the level of mold smell remaining and allow the book to remain sealed in the bag for two more days if the mold smell persists.
Remove the book from the plastic zip-locking bag and place it in a shallow baking pan.
Warm the oven to 250 degrees, then turn the oven off and place the fanned book into the oven until the oven cools completely. The heat from the oven will kill any tiny mold or mildew spores contributing to the remaining mold odor in the book.