Apple iMac (27-inch, September 2013) review: New processors and faster Wi-Fi for Apple's slim desktop - CNET
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 RAM at Amazon.com
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
iMac | 3.2 GHz Core i5 | 27 Inch | Late 2013 - Techable.com
Late 2013 27-inch iMac: Unboxing and Specs (HD) - YouTube
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Apple iMac 21.5-inch and 27-inch (Late 2013) reviews | Macworld
Pre-Owned Apple iMac 21.5-inch Desktop "Core i5" 2.9 (Late 2013) 8GB Memory 1TB HDD ME087LL/A - Best Buy
iMac 21.5-inch Late 2013 – Full Tech Specs, Release Date, and Price
Install memory in an iMac - Apple Support
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com
Differences Between Late 2012 and Late 2013 Aluminum iMac: EveryMac.com
New CPUs, faster Wi-Fi, same flaws: Apple's 2013 iMac reviewed | Ars Technica
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
iMac (27-inch, Late 2013) - Technical Specifications
A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
A pro with serious workstation needs reviews Apple's 2013 Mac Pro | Ars Technica
iMac | 2.7 GHz Intel i5 | 21.5 Inch | Late 2013 - Techable.com
Apple Mac Pro review (2013) - The Verge
Configure your own 21.5-inch Apple iMac (2013) at OWC