Roberts's rhymes with:
blitzes, chatz's, crovitz's, dershowitz's, gates's, holtz's, luntz's, martz's, ovitz's, pitts's, reitzes, schutz's, shortz's, sitzes, waldholtz's, weintz's
Roberts's sounds like:
rebirths, report's, reportage, reports, reports', reproduce, reproduces, reverts, robards, robarts, roberds, robert's, roberts, roberts', robertshaw