Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: Summitfashions Women's Size Sparkling Silver Ballet Flats with Glitter and Small Bow Detail
Product description: Enjoy getting dressed up without having sore feet! These silver glitter ballet flats add the sparkle and shine you want without the pain.
Product feature: Synthetic, Women's Sizing shiny silver glitter ballet flats, Sparkling silver glitter shoes, Small decorative bow with metallic silver trim and bow, Available in Women's Sizing only, Shipping Weight: 2.25 pounds ( View shipping rates and policies ), ASIN: B07CQYH7GW, Date first listed on Amazon: September 17, 2013, Average Customer Review: 1.9 out of 5 stars 2 customer reviews
Product price: $48.94
Product brand: Summitfashions
Target attributes: Silhouette
Answer: attribute: silhouette
value: ballet
source: product feature
attribute: silhouette
value: ballet
source: product title
attribute: silhouette
value: ballet
source: product description
attribute: silhouette
value: flats
source: product description