Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: Lenovo ThinkPad L420 Intel Core i5-2520M X2 2.5GHz 4GB 320GB DVD 14'' NO OS (Black)
Product description: The 14-inch ThinkPad L420 is an attractive option for budget-conscious business users who need zippy performance and a great keyboard.
Product feature: Intel Core i5-2520M 2.5GHz; 320GB SATA; 4GB DDR3, 14" LED display; 1366 x 768; Intel HD Graphics 3000, 802.11B,802.11G,802.11N; No Bluetooth; No OS, Non-Backlit Keyboard; DVD Player; 6 Hours Battery Life, Energy Star Compliant
Product brand: Lenovo
Target attributes: Processor Brand
Answer: attribute: processor brand
value: intel core
source: product title
attribute: processor brand
value: intel core
source: product feature
attribute: processor brand
value: intel
source: product feature