Hi, I'm VERY new to this technology thingy

I have a new galaxy tab 3 with the standard readers hub app. I've downloaded some books and mags and can read them fine. But, there are references in some books that are highlighted, and you should be able to touch them and it will take you to the reference. The references are all downloaded with the book, but, they are all at the back of the book. I can't get it to work when I touch the reference. I have to go to the back pages of the book manually. What am I doing wrong? Do I need another app? All help in REALLY SIMPLE language please

. Thanks