seriously there doesn't seem to be an answer. If you kill the moles you have and your ground is still attractive then more will move in. Various things are said to deter them (windmills, half buried bottles, caper spurge) but i am not sure that there is a definitive answer. We had moles "move through" our garden last year but they seem to have left again, I guess when the food ran out
We have a large country garden,and do suffer with moles.
Now,I don't want to be depressing,BUT,you will never get rid of them completely.
We rake the "hill" (good for potting up plants)off, and pour down a solution of 50% water to 50% jeyes fluid.
The jeyes fluid doesn't kill them but drives them away.
Each pouring lasts about 2 months,and as jeyes fluid isn't that expensive it's a good way.
It works for us (and our garden is 1 acre!) so if yours is smaller it should help you too.