Ical: http://www.google.com/calendar/ical/hc82sdjshuf1ru9f9eqcfq9bvs%40group.calendar.google.com/public/basic.ics
XML: http://www.google.com/calendar/feeds/hc82sdjshuf1ru9f9eqcfq9bvs%40group.calendar.google.com/public/basic