Perhaps you should try some spelling variations:
tenth » tenti, teeth, tentih, texth, testh
tench » tencha, teach, tech
tent » tenti, text, test
benth » beth, bench, bent
bento » benito, benton, bentos
problem » problemas
problems » problemass, problemas
problema » problemasa, problemas

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: Hilbert's (((tenth OR tench) OR tent) OR (benth OR bento)) (problem OR (problems OR problema))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "Hilbert's (((tenth OR tench) OR tent) OR (benth OR bento)) (problem OR (problems OR problema))".
• Adding a wildcard symbol may retrieve word variants: Hilbert's (((tenth OR tench) OR tent) OR (benth OR bento)) (problem OR (problems OR problema))*.