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: Dell TW212 Nvidia Quadro NVS 290 256MB Video Card Precision R5400 T3400 T3500 T5400 T7400 Graphics
Product description: This is a Dell labeled Video Card compatible with the Precision R5400 Desktop
Product feature: Video Card, Precision, R5400, Dell, computer-graphics-cards
Product price: $2.54
Product brand: Dell
Target attributes: DVI Output Type
Answer: attribute: dvi output type
value: None
source: None