Instruction: Given the title, description, feature, price, and brand of a product and a set of target attributes, extract the value of each target attribute from the product information. Output the extracted value and the corresponding source (e.g., title or feature) denoting where the value is extracted.

Input:
Product title: WWE School Backpack
Product description: Ideal for the WWE fan, comes this ultra cool square backpack. Features front and main compartments, hook, padded and adjustable back straps. Made of canvas material, bag measures approximately 15 x 12 inches.
Product feature: measures approximately 15 x 12 inches, padded and adjustable back straps, made of canvas material, Shipping Weight: 1 pounds, ASIN: B00JKKBVWM, Date first listed on Amazon: April 9, 2014, Average Customer Review: 5.0 out of 5 stars 1 customer review
Target attributes: Material
Answer: attribute: material
value: canvas
source: product feature
attribute: material
value: canvas
source: product description