4GB NEMIX RAM Memory for Apple iMac Early & Mid 2009 System Specific Memory - Newegg.com
A-Tech for Apple 4GB Kit (2X 2GB) DDR3 1067MHz / 1066MHz PC3-8500 SODIMM Memory RAM
Early 2009 model iMac Computer, DDR3 8GB (2x4GB) RAM Replacement - YouTube
Memory RAM Upgrade for Apple iMac 27-inch Late 2009 4GB DDR3 SODIMM | eBay
How to UPGRADE Ram on iMac (2009-2011) - YouTube
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
Timetec 8GB KIT(2x4GB) Compatible for Apple DDR3 1067MHz / 1066MHz PC3-8500 CL7 for Mac Book, Mac Book Pro, iMac, Mac Mini (Late 2008, Early/Mid/Late 2009, Mid 2010) SODIMM Memory MAC RAM Upgrade
iMac 21.5" Late 2009 (10,1) - CPU Upgrade E8600 | MacRumors Forums
OWC 16GB (4 x 4GB) PC8500 DDR3 1066MHz SO-DIMMs Memory Compatible with iMac 21.5" and 27" (October/2009) at Amazon.com
Install memory in an iMac - Apple Support
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
Install memory in an iMac - Apple Support
Timetec 16GB KIT(4x4GB) Compatible for Apple DDR3 1067MHz / 1066MHz PC3-8500 CL7 Dual Rank for iMac (Late 2009 21.5-inch / 27-inch) SODIMM Memory MAC RAM Upgrade for iMac 10,1 and iMac 11,1 at Amazon.com
How-To: Boost your Mac's speed and prolong its useful life with easy RAM upgrades - 9to5Mac