Links for Google Maps layer
Google Maps: https://mt1.google.com/vt/lyrs=r&x={x}&y={y}&z={z}
Google Satellite: http://www.google.cn/maps/vt?lyrs=s@1...{x}&y={y}&z={z}
Google Roads: https://mt1.google.com/vt/lyrs=h&x={x}&y={y}&z={z}
Google Satellite Hybrid: https://mt1.google.com/vt/lyrs=y&x={x}&y={y}&z={z}
Google Terrain: https://mt1.google.com/vt/lyrs=p&x={x}&y={y}&z={z}