13“ Retina MacBook Pro review: more pixels, less value | Ars Technica
RAM upgrade and/or SSD drive – what's the benefit?
Apple MacBook Pro (15-inch, 2013) review: Apple's high-end laptop gets better battery life and a lower price - CNET
A-Tech 8GB 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
How to Upgrade the SSD in a 15-inch MacBook Pro w/ Retina display (Mid 2012–Early 2013) on Vimeo