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: CyberpowerPC Business Acclaim BACC300 Desktop (3.5 GHz Intel Core i7-4770K Processor, 16GB DDR3, 2TB HDD, 120GB SSD, Windows 7 Professional) Black (Discontinued by Manufacturer)
Product description: CYBERPOWERPC Business Acclaim BACC300 w/ Intel i7-4770K CPU, 16GB DDR3, NVIDIA Quadro K4000 3GB, 120GB SSD, 2TB HDD, Liquid Cooling, 24x DVDRW, Card Reader & Win 7 Pro 64-bit
Product feature: Intel A4 Processor 3.5 GHz(8 MB cache), 16GB SDRAM DDR3, 2048 GB 7200 rpm Hard Drive, 120 GB Solid State Drive, Windows 7 Professional
Product brand: CyberpowerPC
Target attributes: Processor Speed
Answer: attribute: processor speed
value: 3.5 ghz
source: product feature
attribute: processor speed
value: 3.5 ghz
source: product title