Hands-on with the new $50 Logitech Ergo M575 Wireless Trackball - CNET
Logitech MX Ergo Wireless trackball mouse review | TechRadar
Logitech 910-005177 MX Ergo Wireless Trackball Mouse – Move Text/Images/Files Between 2 Windows and Apple Mac Computers (Bluetooth or USB), Rechargeable, Graphite black: Mice: Amazon.com.au