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: Unionbay Big Boys' Short Sleeve Heaton Poplin Button Up Shirt
Product feature: 100% Cotton, Imported, Machine Wash, Button up short sleeve shirt, Cut and sew detail, 1 chest pocket, Package Dimensions: 9.2 x 7 x 2.3 inches, Shipping Weight: 4 ounces, ASIN: B00I492DEA, Date first listed on Amazon: April 9, 2014, Domestic Shipping: Item can be shipped within U.S., International Shipping: This item is not eligible for international shipping. Learn More, Average Customer Review: 4.5 out of 5 stars 2 customer reviews
Target attributes: Fastening Style
Answer: attribute: fastening style
value: button up
source: product title
attribute: fastening style
value: button up
source: product feature