4GB PC10600 DDR3 1333MHz SO-DIMM Memory Ram Compatible with 2011 MacBook Pro, Mid 2010/2011 21.5" & 27" iMac Models, 2011 Mac Mini (OWC1333DDR3S4GB) at Amazon.com
Timetec 16GB KIT(2x8GB) Compatible for Apple DDR3 1067MHz / 1066MHz PC RAM for Mac Book (Mid 2010 13-inch), Mac Book Pro (Mid 2010 13-inch), iMac (Late 2009 27-inch), Mac Mini (Mid 2010)
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
Apple iMac 27" (Mid 2010) | 32GB RAM - computers - by owner - electronics sale - craigslist
Install memory in an iMac - Apple Support
Apple iMac 2010 8GB DDR3 1333MHz PC3-10600 204-Pin SoDIMM
Apple iMac 2010 (Mid) 21.5-inch (iMac 11,2) SSD ,Ram & OSX Upgrades - ZD Laptop Service Centre
8GB -2x4GB Memory Ram Upgrade for 27" Apple iMac 11.3 Core i5 3.6GHz Mid 2010 | eBay