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: Uni POSCA PC-17K Extra Broad Tip Marker
Product description: Water based poster-paint effect with no odour or smell. Writes on most surfaces: Paper, card, metal, plastic, glass, stone, canvas, fabric etc. Produces an opaque, vivid color. Ink doesn't feather or bleed through paper. Line width 15.0 mm.
Product feature: Mixed, ,, Reversible tips for prolonged use, Non-toxic and water-based, A mixing ball inside the barrel keeps paint consistent, Product Dimensions: 6.3 x 1.1 x 1.1 inches, Shipping Weight: 2.4 ounces ( View shipping rates and policies ), ASIN: B000N6KEZW, Item model number: PX364174000, Date first listed on Amazon: December 7, 2012, Average Customer Review: 1.0 out of 5 stars 1 customer review
Product price: $7.15
Product brand: Uni-ball
Target attributes: Quantity
Answer: attribute: quantity
value: None
source: None