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
Upgrading RAM in Your MacBook Pro 13" or 15" : 19 Steps (with Pictures) - Instructables
Is there a way to upgrade the RAM in an early 2015 MacBook Pro without voiding the warranty? - Quora
Amazon.com: 2015 Apple MacBook Pro with intel I7 (15-inch, 16GB RAM, 256GB SSD)- Silver (Renewed) : Electronics
Apple MacBook Pro with Retina Display (13-inch, 2015) review: Apple's 2015 MacBook Pro is still around for those who want fewer dongles - CNET
MacBook Pro 13" Retina 2.9GHz Logic Board, 16GB, Early 2015 - 661-02357
16GB Kit (2 x 8GB) PC3-14900 RAM for Apple iMac Late 2015 - 27 Inch Retina 5K MK462LL/A - MK462xx/A Memory Upgrade Kit — A-Tech Memory
Logic Board for 2015 Apple MacBook Pro Retina i7 16GB, A1398