Apple Memory Module 16GB DDR4 2400MHz SO-DIMM (2x8GB) - Apple
16GB vs. 32GB MacBook Pro: How Much RAM is Enough? - MacRumors
RAM upgrade considerations for iMac systems - CNET
How to Upgrade RAM on MacBook Pro, iMac & More | AVG
CMS 16GB (2X8GB) DDR3 12800 1600MHz Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® MacBook Pro Core I5 2.5 13" Mid-2012 - A7 at Amazon.com
Adamanta 16GB (2x8GB) Apple Memory Upgrade DDR3L 1600MHz SODIMM Compatible for iMac (Mid 2011, Late 2012, Early/Late 2013, Late 2014, Mid 2015), MacBook Pro (Early/Late 2011, Mid 2012), Mac Mini at Amazon.com