Instruction: First, identify the target attributes from the provided list. Then, scan the product title, description, feature, and brand to extract the values associated with each target attribute. Finally, create a list of dictionaries, each containing the extracted attribute, its corresponding value, and the source where it was found.

Input:
Product title: Spine Book Tower
Product description: Use this unique bookshelf as an artistic focal point in your room. The tall slender design saves space and adds function. Extremely versatile, this tower shelf can work as a towel stand in the bathroom, bookcase in the bedroom, or even a media stand next to the TV. The 11 shelves are constructed of solid metal with a powder coated silver finish ensuring that no matter where you choose to use it, this shelf will always look as good as the day you bought it. This "goes anywhere" storage tower feature shelves that flip up for easy fitting of larger books. Dimensions include: Overall: 16" W x 14" D x 55.25" H; Base: 16" W x 14" D x 1" H; Shelves: 7.75" W x 7.75" D x 4.25" H (each); Spine: 3" W x 1.5" D x 55.25" H. This one-of-a-kind item approximately weighs 35 pounds and can support up to 9 pounds per shelf. Only quality materials and manufacturing will do. Product materials include: Powder-coated tube, sheet metal. Assembly required. Made in China.
Product feature: Features 11 storage shelves that flip up for fitting large books, Vertical, space saving design allows for small space-friendly storage, Contemporary book tower is finished in a silver finish, Assembly required | Constructed from Powder-coated tube and sheet metal, Weighs 35 pounds, supports 30 pounds (per shelf) | Measures 16 inches wide x 14 inches deep x 55.25 inches high
Product price: $13.25
Product brand: Southern Enterprises
Target attributes: Shelf Material
Answer: attribute: shelf material
value: None
source: None