I think my kittens are part Bengal, part American short-hair, but I am not sure. Can anyone help?

All of my kittens have similar markings to those of the Bengal breed, especially the darker two, but the gray two are a puzzlement due to their coloring. I am pretty sure they are part American short-hair, too, but it is so hard to tell. They all have more of the personality of a Bengal than an American short-hair and they portray a lot of other Bengal characteristics, as well. How would I find out what breed(s) they really are? I have pictures.