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: MAVIS - THOMAS THE TANK WOODEN RAILWAY
Product description: Mavis is back. A re-introduced version of the original. This is the exact same product from the same manufacturer - only a new item number. Part of the Thomas Wooden Railway
Product feature: Mavis wooden engine
Product price: $74.99
Product brand: Thomas & Friends
Target attributes: Battery Type
Answer: attribute: battery type
value: None
source: None