Instruction: Using the product's title, description, features, price, and brand, identify and retrieve the values associated with a specified set of target attributes. Output the extracted values along with their respective sources (e.g., title or feature) indicating where each value was found.

Input:
Product title: 2013 American Silver Eagle Proof
Product feature: 2013 American Silver Eagle Proof Coin, Eligible for IRA, Includes Original Velvet Collectors Box with Certificate of Authenticity, Just Released January 2013, Limited Silver Supplies makes continued production uncertain
Product brand: U.S. Mint West Point
Target attributes: Coin Material
Answer: attribute: coin material
value: silver
source: product title
attribute: coin material
value: silver
source: product feature