There seem to exist many bibliographic reference styles and many universities have their own guidelines too. I wonder, whether there exist any universal guidelines for formatting bibliographic references in publications?
That said, there are some common approaches—the Modern Language Association and Harvard formats are quite common in the humanities. The sciences have more widely spread systems, but I think the most common I've seen is the "abbreviated style," containing authors, journal, volume and page info and year. (There are some variations within that style based on different publishers, and some publishers, like ACS, are now starting to take advantage of electronic distribution by including full titles.)
The answer is no. Within fields, there are often a single style which makes some approaches and components more common or even that makes a single style dominant.
Get yourself some software like BibTex, EndNote, Zotero (my personal favorite), or similar so that you can simply rely on someone else to automate importing the data into a database and outputting according to whatever rules a particular journal or venue requires.
As aeismail said, there are no truly universal rules and the bibliographic reference styles differ across scientific disciplines, and even within these there is often large variation. So normally, you need to consider the journal/conference/... the publication you are writing is aimed at and consult their rules. Most of the time, you will find quite strict requirements articulated in the venue's "submission guidelines", or "author's corner" sections - usually on their website. If still not sure, contact the responsible editors/PC chairs to advise you.
As everyone says, there are no universal systems, although there are a few very popular systems. Of course you should use reference software, but if you are asking which style you should use for general purpose citations outside of publishing, I would just pick one of the most popular, depending on your discipline.
- Chicago style seems flexible and perhaps the least field specific.
- APA style is popular in the life sciences and psychology, of course. But, I don't know if it is so popular in the humanities.
- MLA style seems to be the most popular in the humanities.
If you are not instructed to use a specific one, all of them give the necessary information in a bibliography/reference list format (that is, the full title, authors, dates). I think the issue that might be field specific is in-text citations, but that is not your question. If you pick one and use it consistently in any given document, I am certain it will be internationally understood.
Keep in mind you do not need to learn all the details- just select the option in the software and make sure any imported references (from old PDF's, etc.) are correct. I like Mendeley.