I know this is going to sound crazy, but this is how I have gotten several stray kittens that were very wild to come to me...
I sit very still and meow to them in a high pitched kitten meow. For some reason they must think or remember this type of meow from their sibblings I'm assuming, and it has worked every time. It might take a little time sitting and meowing to them...and dont worry what your neighbors are going to think of you, mine have come to understand what I'm doing, they just call me the crazy cat lady now, LOL! But seriously though, give it a try and see if that works.