Googling for "Romanian stopwords" brings up a good number of resources.
If you want to do this yourself, you simply need to find words which are common in all genres of text. (The article you link to has a rather poor explanation of what stop words are.) Good candidates are articles, particles (if your language has them, and they occur in isolation), conjunctions, pronouns, and some types of adverbs.
Automatically Building a Stopword List for an Information Retrieval System (Rachel Tsz-Wai Lo, Ben He, Iadh Ounis; University of Glasgow, 2008) (PDF) documents an automatic method for finding stop words. I have not looked at the method or its results.
https://github.com/berkmancenter/mediacloud/blob/master/script/mediawords_generate_stopwords.pl seems to have an implementation. (The comment has other names than the article; not sure what's up with that.)