Perhaps you should try some spelling variations:
tenth » teeth, tench, texth, kenth, tenh
benth » bento, bench, bent
beth » both, beta
tenti » texti, kenti, teni
tent » text, kent, ten
test » text, west, best
problem » problema, problems
problemas » problemaas, problemsas

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "Hilbert's (((tenth OR (benth OR beth)) OR tenti) OR (tent OR test)) (problem OR problemas)~".
• Adding a wildcard symbol may retrieve word variants: Hilbert's (((tenth OR (benth OR beth)) OR tenti) OR (tent OR test)) (problem OR problemas)*.