You can use this link to add our calendar to yours.
1 Open Google Calendar.
2 On the left side, click Other calendars.
3 In the Add a friend's calendar enter: EMAG2017.MENSA@GMAIL.COM and press Enter.
4 The calendar is already shared with the public the EMAG calendar will be added on the left side under "Other calendars."
5 You can select a color for this calendar to make it clear the items are from the EMAG calendar. You can also hide and show it.
6 NOTE: to make clear for yourself what you have booked, you can hover over the top of a calendar item and then click. You get the option to copy the item to your own calendar. This way these items you booked are a different color and you can also easily see changes in times when the items differ.
For iphone: follow the instructions on this website: https://www.lifewire.com/how-to-sync-google-calendar-with-iphone-calendar-1172187