These Hardy Boys mystery books are great for any fan of classic detective stories. To use them, simply pick up a book and start reading. Enjoy getting lost in the exciting mysteries. When handling the books, be gentle to avoid further wear. Since some books have minor damage like creases and stains, it's best to keep them away from liquids to prevent further staining. Store the books in a dry and cool place to maintain their condition. You can stack them neatly on a bookshelf, but be careful not to put too much pressure on the spines. This way, you can enjoy these vintage books for a long time.