GOOGLE APPS: How to add others/coworkers calendar

1. log in to your email
2. from your email hit link calendar
3. then there will be a new window/tab appeared with your calendar.
4. On the left-pane of calendar window, you will find other calendars. 
5. Under other calendars there's a box to add a co-workers calendar.
6. Just type in coworkers name. For example: azizi. It will appear possible name for Azizi.
7. You just select as desire.
8. Then you are done.