A-Tech 16GB (2x8GB) RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com
Timetec Hynix IC 8GB KIT(2x4GB) Compatible for Apple DDR3 1333MHz PC3-10600 for Early/Late 2011 13/15/17 inch MacBook Pro, Mid 2010 Mid/Late 2011 21.5/27 inch iMac, Mid 2011 Mac Mini - Newegg.com
2009 27" iMac Core i7 can take (2x8GB) 16GB DDR3 1600Mhz RAM? | MacRumors Forums
Apple 16GB (4 x 4GB) DDR3-1333 MHz PC3-10600R ECC– Cloud Ninjas