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: BlackBerry Curve 8520 Violet WiFi Unlocked GSM QuadBand Bar Cell Phone
Product description: A classic and aptly named release from Rhythm in Motion, the BlackBerry Curve 8520 features everything you expect from a reliable Smartphone, including a digital camera, frontal QWERTY keyboard, multimedia capabilities, and memory expandable to up to 32GB via a microSD card slot. Whether you need to keep track of appointments, efficiently compose emails or share files, the BlackBerry Curve 8520 is designed to deliver it it.This Bluetooth enabled phone will even help you put safety first, allowing you to keep your hands free while driving, ensuring that you keep your attention on the road. And, with support for GPRS, GSM, and EDGE networks, this Quad Band phone will keep you in touch across the globe, whether you find yourself in North America, Europe, or Asia. With an easy to navigate, user friendly interface, the famous BlackBerry Messenger and many other great features, the BlackBerry Curve 8520 will keep you in touch, in the loop, and productive regardless of where each day may take you.
Product feature: Cellular Band - Quad-Band 850 / 900 / 1800 / 1900 Mhz
Product brand: BlackBerry
Target attributes: Front Camera Resolution
Answer: attribute: front camera resolution
value: None
source: None