I bought the first book from Maxine Rosenthal called One Block Wonders. The book gives excellent advice on picking fabrics and technique for making the quilt and also provides many examples that encourage you to add your own touch. However that book shows the hollow cubes but does not explain how to make them. Her next book, One Block Wonders Encore, gives directions for the hollow cubes, and her last book, One Block Wonders Cubed, focuses in on the cubes. I only have the first book, but if I were to buy one of her books now I would probably get the 2nd or 3rd. They're all available on Amazon.