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: Lenovo Y550P 324156U 15.6-Inch Laptop (Black)
Product description: Small on the outside. Big on the inside. INTRODUCING THE LENOVO IDEAPAD Y550 NOTEBOOK. Have your own private movie theater and hear your music concert style—wherever you like. The Lenovo IdeaPad Y550 notebook comes with OneKey Theater — a single button that effortlessly optimizes your audio and video settings for high-definition entertainment. Plus, Dolby Home Theater brings the concert hall into your PC, with crystal-clear surround sound effect, rich bass and wide audio spectrum. Go on, let the show begin. Best of all, it’s from Lenovo, makers of the award-winning ThinkPad business notebook. And with Windows 7 Lenovo Enhanced Experience certification, you’ll appreciate fast boot and shutdown, rich multimedia capabilities and easy system maintenance tools.
Product feature: Intel Core i7 Processor 1.6GHz, 4GB DIMM RAM, 500GB 5400RPM Hard Drive, 15.6-Inch Screen, GeForce GT, Windows 7 Home Premium 64-bit, 4 hours Battery Life
Product brand: Lenovo
Target attributes: Number of Cores
Answer: attribute: number of cores
value: None
source: None