First, please copy the link below. Then follow the instructions for your calendar software:

https://calendar.google.com/calendar/ical/grvhq7ee33rm7mvfegufvihsj4%40group.calendar.google.com/public/basic.ics
(right-click --> Select "Copy Link Location")

Google Calendar Instructions (Click on the "Add using a link" section)
Microsoft Outlook Instructions (Scroll down to the "Add an Internet Calendar Subscription to Outlook" section)
iCalendar Instructions (Click on the "Subscribe to other calendars" section)

Please Note: You can safely ignore any error messages while importing a feed into Outlook 2007. This will not affect the functionality of the feed.