MacBook Pro: How to remove or install memory - Apple Support
16GB 8GB 4GB DDR3 1600MHz RAM for Apple MacBook Pro Mid 2012 sodimm Memory lot | eBay
Apple MacBook Pro 13.3" (500GB HDD, Intel Core i5 3rd Gen., 2.5GHz, 4GB RAM) Laptop - Silver - MD101LL/A (Mid 2012) for sale online | eBay
Logic Board - Mid 2012 15” MacBook Pro 2.3GHz i7 661-6491 MD103LL/A BAD RAM SLOT | eBay
Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
Mid-2012 Macbook Pro 16GB RAM Upgrade How To - YouTube
A-Tech 16GB Kit (2x8GB) RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
Memory RAM Upgrades for MacBook Pro (2012 - Late 2016)