No referrals, but I do have some experience with it. Our last house had big trees behind it with roots stretching up to the back of the house. You couldn't really keep it watered enough to help the foundation. The back half of the perimeter of the house was always too dry due to the roots.
This is the part I don't know which is better. We moved shorty after, so I admit I didn't fully research it and I wasn't paying for it either. Engineer made 2 recommendations:
1) basically dig a trench parallel with the house half way between the house and the trees deep enough to cut all the roots headed towards the house. Supposedly this didn't hurt the trees and got cut the roots far enough away from house they wouldn't effect the soil around the foundation for 4-5 years. Trench was filled back in with first, so no barrier was installed.
2) do the same process but fill the trench with a barrier. According to engineer, the roots will find a way around the barrier eventually. It will take longer, but then it is harder to do another barrier in the future. You would have to build a separate barrier the next time and will be deeper since the roots went under the first barrier.
I was told there was no permanent fix. I approved option one. It was the engineers recommendation and we were moving anyway. Normally I research everything, but was lazy this time about so I don't know which way I would of gone if we were staying.