Why can´t others see the event link (URL web) on a shared calendar?

Why can´t others see the event link (URL web) on a shared calendar?

Hello, when I add an event on my calendar, I also can add a link (URL web) as an aditional information to the event, but when I share the calendar to my peers, they can't see the link that I just added on the event...

What can I do to let my guests see the link?? 

Thanks in advance for your help and for the great app!!

Cesar