Instruction: Given the title, description, feature, price, and brand of a product and a set of target attributes, extract the value of each target attribute from the product information. Output the extracted value and the corresponding source (e.g., title or feature) denoting where the value is extracted.

Input:
Product title: Thinkpad Z60T 2511 Pentium M 740 1.73 Ghz-ram 512 Mb-hd 80 Gb-DVD-writer-cellula
Product description: LENOVO (2511FEU) ThinkPad Z60t 2511 Pentium M 740 1.73 GHz-RAM 512 MB-HD 80 GB-DVD-Writer-cellula
Product feature: 1.73 Ghz-ram 512 Mb-hd 80 Gb-DVD-writer
Product brand: Lenovo
Target attributes: Screen Size
Answer: attribute: screen size
value: None
source: None