OWC 8GB (2 x 4GB) PC12800 DDR3L 1600MHz SO-DIMMs Memory Compatible with 2011-2015 iMac, 2011-12 Mac Mini, and 2011-2012 MacBook Pro (Non-Retina Display) Models (OWC1600DDR3S08S) at Amazon.com
Crucial 4GB Kit (2GBx2) DDR3/DDR3L 1066 MT/s (PC3-8500) SODIMM 204-Pin Memory For Mac - CT2K2G3S1067M at Amazon.com
SK Hynix 4GB HMT451S6AFR8A-PB DDR3 1Rx8 PC3L-12800S Laptop Memory at Amazon .com