FreeKB - Logitech Resolve "There is no Unifying receiver plugged into your computer"
Ask a Swiss: How to connect a non-Unifying Logitech keyboard & mouse to a new dongle
HGYCPP New Usb Receiver Wireless Dongle Receiver USB Adapter for Logitech mk270/mk260/mk220/mk345/mk240/m275/m210/m212/m150 Mouse Keyboard Connect - Walmart.com
Download Logitech Unifying Software for Mac | MacUpdate
Amazon.com: Unifying Receiver for Mouse and Keyboard Compatible for Any Logitech Product That Display The Unifying Logo (Orange Star, Connects up to 6 Devices) : Electronics