To add to your phone or other device, you must "subscribe" to the iCal link:

https://calendar.google.com/calendar/ical/c_2819998861e9e9b8fcca6fab5372dd70a4d9016d5cfe8f844a0f1f142df6646f%40group.calendar.google.com/public/basic.ics

Unsure how to subscribe?  Search online. An example search string may be "subscribe to a calendar in iPhone".  Or find a friend who is technically savvy. Our intention is to simply provide links, not individual device or phone support.