You could have all 71 titles installed at the same time!

Click the Field Guide icon to see the titles installed, then make your selection. Click Help to manage your license keys.

If you still have a problem, please submit a help desk ticket and tell us exactly what happens when you try to add a second title.

By the way, if you own Guide to Birds of North America, then you can use the filter to see any of the "subsets" we offer as additional titles.