Scott Lowther presents NASA's Nova concepts in a series of Aerospace Project Review blog posts: Class I, Class II, and Class III. I've attached a lo res copy of the Class III page, mostly because of the cute, stubby, air-breathing ram-jet or maybe a ram-rocket (on the left). You can get high res copies of the images by ordering issues of his Aerospace Projects Review (APR), as identified in the sources above.
If you aren't familiar with the APR, you can read about one that I purchased here.
Just for the record, I wanted to clarify that Nova is not an acronym, although I have presented the name in all caps several times (I'm not going to bother fixing this error). I have also referred to the Nova as a solid rocket heavy lift vehicle. That is not incorrect but it also not the entire story. If you look at all my posts on the subject, the vehicles have a wide variety of form factors. That's because Nova refers to a whole series of design options for the unrealized Saturn V follow-on. These designs understandably included a wide variety of propulsion options. The following links provide the historical background.