8GB (2 X 4GB) DDR3 1600MHz PC3-12800 240-pin Memory RAM DIMM Kit for Desktop PC by NEMIX RAM at Amazon.com
New 4GB/8GB DDR3 RAM – Epic Repair
Crucial 8GB (2 x 4GB) DDR3L 1600 (PC3L 12800) Desktop Memory Model CT2K51264BD160B - Newegg.com
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
How much RAM does my laptop need? 4GB vs. 8GB vs. 16GB, etc. | PCWorld