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: HP Mobile DVDRW (R DL) / DVD-RAM Drive - External (701498-B21)
Product description: Hpe mobile - disk drive - DVDRW (R DL) / DVD-RAM - USB - external - for ProLiant DL180 Gen9, DL380 Gen9, DL560 Gen9
Product feature: Interface: USB, Optical storage: dvdrw (R DL) / DVD-RAM, Designed for: proliant DL180 Gen9, DL380 Gen9 high performance, DL560 Gen9, DL560 Gen9 base, DL560 Gen9 entry, DL560 Gen9 performance
Product price: $6.71
Product brand: HP
Target attributes: Style
Answer: attribute: style
value: None
source: None