Thanks for the reply Valloric.
I must admit I'm not real good at Sigil and formatting in general so I don't know what styles are associated with the CSS classes. In fact I don't even know what CSS classes are! I just copied the code that was before and after the book title because the book title displayed in bold.
It's not really a big issue though and with more playing around and reading I think I will eventually learn enough to work it all out.