Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
van thanh » ban thanh, van tuan
nam duoc » nam thuoc, da duoc, dat duoc
tu sach » thu sach, su sach, te sach
cao duc » dao duc, cao suc, giao duc
sach ly » sach y, sach lo, sach ty
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
vang ma » nang ma, sang ma, rang ma
cuc te » cua te, cuc thue, cuc tieu

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 ly ((vang ma) OR (tang ma)) hoi. hieu ve ((nam duoc) or (cao duc)) van thanh tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly ((vang ma) OR (tang ma)) hoi. hieu ve ((nam duoc) OR (cao duc)) van thanh tai cuc te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly ((vang ma) OR (tang ma)) hoi. hieu ve ((nam duoc) or (cao duc)) van thanh tai cuc te".
• Adding a wildcard symbol may retrieve word variants: tu sach ly ((vang ma) OR (tang ma)) hoi. hieu ve ((nam duoc) or (cao duc)) van thanh tai cuc te*.