Instruction: First, identify the target attributes from the provided list. Then, scan the product title, description, feature, and brand to extract the values associated with each target attribute. Finally, create a list of dictionaries, each containing the extracted attribute, its corresponding value, and the source where it was found.

Input:
Product title: Dunlop DEN1356 Nickel Wound Electric Guitar Strings, Extra Heavy, .013–.056, 6 Strings/Set
Product description: String up with Dunlop Electric Guitar Strings, and hear the tone you've been missing! Dunlop creates these nickel-plated steel strings to bring you top-notch tone, with a focused low end, aggressive mids, and crisp highs. These Dunlop electric guitar strings have excellent string-to-string balance, and a dynamic responsiveness that really lets you express yourself. No matter what style you play, there's a great-sounding set of Dunlop Electric Guitar Strings for your guitar! Gauge: .013, .017, .026 .036, .046, .056.
Product feature: Brand: Dunlop, Product Code: DEN1356, DEN1356 - Nickel Plated Steel Ultra Heavy Electric Guitar 6 String Set, .013-.056
Product price: $7.78
Product brand: JIM DUNLOP
Target attributes: Winding Material
Answer: attribute: winding material
value: nickel wound
source: product title
attribute: winding material
value: nickel plated steel
source: product feature
attribute: winding material
value: nickel-plated steel
source: product description