Instruction: Using the product's title, description, features, price, and brand, identify and retrieve the values associated with a specified set of target attributes. Output the extracted values along with their respective sources (e.g., title or feature) indicating where each value was found.

Input:
Product title: HP 671869-002 109-C07751-20 ATi Radeon 7450A Exige 4 MXM-A Graphics Card
Product description: HP 671869-002 109-C07751-20 ATi Radeon 7450A Exige 4 MXM-A Graphics Card Manufacturer: HP Part Number: 671869-002 M/PN: 109-C07751-20 Compatible Model: HP
Product feature: HP 671869-002 109-C07751-20 ATi Radeon 7450A Exige 4 MXM-A Graphics Card, Manufacturer: HP, Part Number: 671869-002, M/PN: 109-C07751-20, Compatible Model: HP
Product brand: HP
Target attributes: Length
Answer: attribute: length
value: None
source: None