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
Review: 13-inch MacBook Air (mid-2013) - 9to5Mac
MacBook Air 11" Mid 2013 Teardown - iFixit
Upgrading RAM on a First Generation MacBook Air - YouTube