Battery Replacement for Apple iPhone 4 / iPhone 4S Battery | eBay
Looking inside an iPhone 4/4S battery | Rip It Apart - Jason's electronics blog-thingy
Mobile Phone Battery 1420mah For Iphone 4 Battery 4s Battery Replacement Батарея Для Телефона Original Batterie Bateria - Mobile Phone Batteries - AliExpress
All Differences Between the iPhone 4 and iPhone 4S: EveryiPhone.com
Amazon.com: MFI-Apple Certified - ibattz Mojo Vogue Removable Battery Case for iPhone 4 and 4S White 1700mAhX2 fits all version of iPhone 4S/4 : Cell Phones & Accessories