REK bookcase by Reinier de Jong
REK书架神奇之处在于，其独特的Z字形模块可以通过简单的推拉相互嵌入，从而有不同的书架形态。
REK is a bookcase that grows with your book collection. The more books the bigger the bookcase gets. The zigzag shaped parts slide in and out to accommodate books in the resulting voids. Also the books can be arranged according to their sizes. The narrow spaces are excellent for magazines.