Amazon.com: Timetec 16GB KIT(2x8GB) Compatible for Apple DDR3 1333MHz PC3-10600 CL9 for Mac Book Pro (Early/Late 2011 13/15/17 inch), iMac(Mid 2010, Mid/Late 2011 21.5/27 inch), Mac Mini(Mid 2011) MAC RAM Upgrade :
Amazon.com: Timetec 32GB KIT(4x8GB) Compatible for Apple DDR3 1333MHz PC3-10600 CL9 for iMac (Mid 2010 27 inch, Mid 2011 21.5/27 inch) SODIMM Memory Module MAC RAM Upgrade for iMac 11,3 / iMac 12,1 / iMac 12, 2 : Electronics
How to Upgrade Memory in a 21.5-inch or 27-inch iMac (Mid 2010) - YouTube
New 16GB 4x4GB Memory Apple iMac (21.5 and 27-inch, Mid 2011) PC3-10600 at Amazon.com
Amazon.com: Timetec 8GB KIT(2x4GB) Compatible for Apple DDR3 1333MHz PC3-10600 for Mac Book Pro (Early/Late 2011 13/15/17 inch), iMac (Mid 2010, Mid/Late 2011 21.5/27 inch), Mac Mini(Mid 2011) RAM Upgrade : Electronics
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
CMS 32GB (4X8GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core I7 3.4 27-Inch (Mid-2011) - C12 at Amazon.com
Install memory in an iMac - Apple Support
NEMIX RAM 32GB SODIMM Memory Upgrade Kit (4x8GB) DDR3 1333MHz PC3-10600 CL9 Compatible for Apple iMac (Mid 2010 27 inch, Mid 2011 21.5/27 inch) for iMac 11,3 / iMac 12,1 / iMac 12, 2 at Amazon.com
Maximum memory for 2011 iMac - Ask Different
16GB -2x8GB Memory Ram Upgrade for 27" Apple iMac-12.2 Core i5 2.7GHz Mid 2011 | eBay