Crucial 8GB Single DDR3 1333 MT/s (PC3-10600) CL9 Unbuffered ECC UDIMM 240-Pin 1.35V/1.5V Server Memory CT102472BD1339 at Amazon.com
A-Tech 4GB RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010, Mid 2011, Late 2011), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Module at Amazon.com
Server 8GB DDR3-1333 RAM for sale | eBay
8GB 2x4GB MacBook Pro 2011 Compatible Memory DDR3-1333 PC3-10600 SODIMM by NEMIX RAM at Amazon.com
A-Tech 8GB (2x4GB) RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010, Mid 2011, Late 2011), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com
8GB G.Skill DDR3 PC3-10666 1333MHz Ripjaw Series CL9 (9-9-9-24) Dual Channel kit at Amazon.com