Perhaps you should try some spelling variations:
sang tao » hang tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
dan vat » dang vat, van vat, dan va
cac tuc » cac toc, cac tu, cac tac
hieu va » lieu va, hieu qua
hieu ve » hieu van
tao hoi » tao khoi, tao boi, tay hoi
ky sang » ky nang, ky dang, ky tang
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau
cua tu » cua tuc, cua su, cua te
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky sang tao hoi. ((hieu ve) or (hieu va)) cac tuc va dan vat ((cua tu) OR (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang tao hoi. ((hieu ve) OR (hieu va)) cac tuc va dan vat ((cua tu) OR (cua cu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang tao hoi. ((hieu ve) or (hieu va)) cac tuc va dan vat ((cua tu) OR (cua cu))*".