Usually, when Russian borrows words from Latin, it uses the accusative form of Latin nouns and adjectives, and replaces the Latin endings with Russian ones. There are numerous exceptions to this rule, but for the most part, it works.

According to this rule, the "correct" form is *референтный*, which is indeed the only form that was in use before mid-80s.

That said, many Russian publications in the 90s and thereafter, just calqued or even borrowed English "reference center", which gave *референсный центр* and *референс-центр*, respectively.

I don't think there's a lot of difference between the two, but *референтный* is both older and more aligned with Russian scientific traditions.