21.5" iMac Mid-2014 1TB SATA SSD Upgrade – UKSL MacLab
Install memory in an iMac - Apple Support
Apple iMac 2014 (Mid) Core i5 1.4Ghz 21.5-inch 14,4 SSD & macOS X Upgrades - ZD Laptop Service Centre
Apple iMac (21.5-inch, 2014) review: A price cut for the 21-inch iMac makes it a mainstream machine - 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
DIY Bundle - 1TB OWC 6G SSD and HDD Kit for 21.5-inch iMac
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
New 21.5-inch iMac least repairable yet due to lack of RAM, hard drive upgradability - 9to5Mac
A-Tech 32GB (4x8GB) RAM for Apple iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com