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: Nike Men's Free Trainer 3.0 Training Shoe
Product description: Nike Men's Free Trainer 3.0, HYPER RED/VOLT-BLACK
Product feature: Synthetic, Shipping Information: View shipping rates and policies, ASIN: B00B4YKPJM, Date first listed on Amazon: January 23, 2013, Average Customer Review: 4.7 out of 5 stars 9 customer reviews
Target attributes: Toe Style
Answer: attribute: toe style
value: None
source: None