Most of the time clicking on a resource will generate a Raven login screen for you to complete and then take you through to the resource.
If you have trouble accessing an ebook or an article when you're not on the Cambridge network, test your Raven access and contact the UIS Service Desk if it isn't working. If your Raven access works but the resource doesn't, contact the eresources team and let them know what you're trying to access and what the problem is.