I believe they don't have middle names:Ruth Joan Bader GinsbergStephen Gerald BreyerJohn Paul StevensDavid Hackett SouterAnthony McLeod KennedyWilliam Hubbs RehnquistClarence ThomasAntonin Scalia
oops, I skipped Sandy. I edited to take care of it.
Are you sure your professor isn't trying to trick you? I've found all the others many times over, but haven't been able to find those two.