Which are the most relevant sources on the goals of university and their relation to its origins and evolution?
Germany has had the model of the Humboldt ideals. Unfortunately, it has now become slowly eroded through the Bologna process of educational reform and unification in Europe. If you want details, these topics are important and influential and you should look up the terms Humboldt ideal and Bologna on the web.

However, in a nutshell, the Humboldt ideal is about educating enlightened citizens, both in terms of expanding one's personal horizon as well as contributing to society. It is a highly influential and (in my opinion) beneficial way of looking at university education. 

Developing the personality of the students is the foremost goal of this way of thinking; for which, of course, the development of a skill set is an important, but not the only or ultimate component. Responsibility for the society at large is part of it, as well. Enlightenment means here that, of course, the individual can and should identify as an individual how to balance the different components. 

The "elite" may be implied here, but should not be understood as a privilege rather than a responsibility and duty. Ultimately, the ideal would be that every single member of the society would belong to this elite in their individual responsibility for the world around them. Of course, this is illusory in reality, but it is clear that this is the goal to aspire to.

In short, being educated in the Humboldtian sense means that you understand the world around you, and you can meaningfully interact on things outside your immediate reach. 

For people who are not interested in anything but their immediate agenda, my question would be why they are considering themselves at all "students" at "university". After all, "student" means "the zealous"; and "university" is not by chance related to "universal".