"studies so far" is a perfectly correct and usable phrase in written English.
For example, you could say: "Studies so far have indicated that the species is endangered."
Currently, it is designated as wetlands, and the impact studies, so far, have prevented any development.
That is one reason the studies so far have been inadequate.
Still, studies so far have come up with differing patterns of brain activation.
But studies so far have found that claim to be little more than wishful thinking.
These studies so far have relied on self-reported use of hearing aids.
But studies so far have failed to demonstrate a cardiac benefit to the drugs.
Very few studies, so far, are reported on this aspect.
Previous studies so far used CNNs for classification.
As monotherapy, however, anti-angiogenic treatment lacked efficacy in randomized clinical studies so far.
However, few studies so far have examined what factors regulate its structure.
Previous theoretical studies so far have largely been concerned with fully in-filled tubes.
