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: Harriton M520 Men's Millennium Twill Shirt
Product description: 4.5 oz., 100% cotton. Long-sleeves. Flat-felled seams at sides and underarm. Dyed-to-match body color, rimmed buttons and shirttail hem. Back yoke. Button-down collar. Left-chest pocket. Two-button adjustable cuffs.
Product feature: 100% Cotton, Fabric Content-100% Cotton, Logo-No, Buttondown Collar-Yes, Fabric/Knit Type-Twill, Gender-Unisex/Male, ASIN: B006HT2QE6, Date first listed on Amazon: February 29, 2012, Average Customer Review: 2.9 out of 5 stars 2 customer reviews
Product brand: Harriton
Target attributes: Fastening Style
Answer: attribute: fastening style
value: buttondown
source: product feature
attribute: fastening style
value: button-down collar
source: product description