Multi-Room Audio Group Setup for Google Home and Chromecast Audio - YouTube
Multi-Room Audio Comes to Chromecast Video, Google Home, and Smart Display Devices - Thurrott.com
Multiroom Support for Chromecast and Audio Extraction for Subwoofer -OZ
Gadget & Gear - Google Chromecast 3rd-gen brings new design, multi-room audio BDT 3990/- Its 15 percent faster than its predecessor, and it supports 1080p video at up to 60 frames per
Multi-Room Audio on Chromecast devices offer no Video -OZ
Chromecast Audio review: The ultimate audio streaming dongle is better than ever - CNET
Google Fires At Sonos, Adds Multi-Room Support To Chromecast Audio | TechCrunch