4GB (1x4GB) DDR3-1333MHz PC3-10600 2Rx8 SODIMM Laptop Memory by NEMIX RAM at Amazon.com
OWC 8 GB (2 X 4GB) ram PC8500 DDR3 1066MHz sodimm 204-pin Memory Upgrade Kit, (OWC8566DDR3S8GP), Compatible with MacBook Pro, MacBook, Mac Mini and iMac at Amazon.com
PC3-10600 DDR3 1333 8GB Kit (2x4GB) RAM PC3 10600S 1333MHZ 2Rx8 204-pin 1.5v 4GB Memory Upgrade for Laptop at Amazon.com
4GB DDR3 1600Mhz Laptop Memory Ram+Cooling Vest for Laptop Notebook - Walmart.com