How to upgrade RAM / Memory on a 2010 iMac Core i3 i5 i7 (21.5in & 27in) - YouTube
iMac Intel 21,5" Late 2011 (EDU) EMC 2496 - used original spareparts for Macs
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
RAM Upgrade for iMac Mid 2011 21.5-inch | MacRumors Forums
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
iMac (Intel-based) - Wikipedia
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
Memory Upgrades for Apple iMac 2011 Up to 32GB
Upgrade your iMac's RAM in less than 5 minutes - YouTube
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac
Install memory in an iMac - Apple Support
Memory Upgrades for Apple iMac 2011 Up to 32GB
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com