New CPUs, faster Wi-Fi, same flaws: Apple's 2013 iMac reviewed | Ars Technica
Why Not Apple Ram
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
How to Upgrade iMac RAM: 2012-2022: EveryMac.com
iMac RAM Upgrade mixing different memory sticks: 27” iMac late 2013 - YouTube
iMac 2013 Model Ram Upgrade - YouTube
For These 20-Inch And 17-Inch Models
16GB -2x8GB Memory Ram Upgrade 21.5" Apple iMac-14.1 Core i5 2.7GHz Late 2013 | eBay
Install memory in an iMac - Apple Support
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
Shop Imac 2013 Ram Upgrade | UP TO 51% OFF
How to Upgrade iMac RAM: 2012-2022: EveryMac.com
NEMIX RAM 16GB Kit (2x8GB Upgrade) DDR3-1600 SODIMM PC3-12800 for Apple MacBook Pro Mid 2012 / iMac Late 2012 / iMac 2013, Late 2014, Mid 2015, Mac Mini Late 2012 at Amazon.com
Apple iMac 21.5-inch and 27-inch (Late 2013) reviews | Macworld
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
How To Upgrade RAM in a Mac | Macworld
Timetec 32GB KIT(4x8GB) Compatible for Apple DDR3L 1600MHz PC3L-12800 CL11 for iMac (Mid 2011, Late 2012, Late 2013, Late 2014 Retina 5K, Mid 2015 Retina 5K) SODIMM Memory Module MAC RAM Upgrade at Amazon.com
2013 iMac teardowns reveal SSD slots, soldered-in CPU in the 21.5” model | Ars Technica