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: Gateway 504GR Desktop PC
Product description: Includes: premium multimedia keyboard, 2-button wheel mouse, amplified stereo speakers, Microsoft Windows XP Home Edition Service Pack 2, Works 8.0, Money 2004, Picture IT! Premium 9.0, PowerDVD, Nero 6 Suite, & more. Gateway 504GR Desktop PC - This desktop PC features an Intel Pentium 4 processor 530 (3.0 GHz) and 512MB of 400MHz DDR SDRAM. Enough power to handle most any computer application. It also features a 16x double layer DVD writer. Giving you the ability to backup large amounts of data easily, as well as tackle creative projects - like making your own DVD movies! Intel Graphics Media Accelerator 900 with DirectX 9 support and up to 224MB of shared video memory (memory is taken from the main RAM) Intel High Definition 6-Channel Audio 200GB Serial ATA 7200 RPM HDD 16x Double Layer DVD Writer - up to 16x DVD+R, 4x DVD+RW, 12x DVD-R, 4x DVD-RW, 48x CD-R, & 24x CD-RW CD-ROM Drive - up to 48x 8-in-1 Digital Media Manager with a built-in USB 2.0 port - supports Secure Digital (SD), Smart Media, Micro Drive, Memory Stick, Memory Stick Pro, Compact Flash, & Multimedia Card 56k v.92 Fax Modem Ports - 10/100 Ethernet, 7 USB 2.0 (2 in front), 1 VGA, 3 FireWire (2 in front), 1 Serial, 1 Parallel, 2 PS/2, & 5 Audio (2 in front) Slots - 1 x16 PCI Express (available), 1 x1 PCI Express (available), & 2 PCI (1 available) Bays - 4 3.5 (2 available) & 2 5.25 (occupied) Unit Weight - 23 lbs.
Product feature: Monitor Not Included, Intel Pentium 4 processor 530 supporting Hyper-Threading technology (3.0 GHz), 1MB L2 Cache, 800MHz FSB, 512MB of 400MHz DDR SDRAM (expandable to 4GB)
Product brand: Gateway
Target attributes: Monitor Size
Answer: attribute: monitor size
value: None
source: None