Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
nuoc sach » nguoi sach, hoc sach, cuoc cach
thanh tai » thanh hai, thanh toan, doanh tai
hieu cua » dieu cua, bieu cua, hieu ca
ty hang » ly hang, thi hang, thu hang
cau doi » cau hoi, cau do, cau noi
doi van » do van, doi va, doi ban
ca viet » va viet, co viet, hoa viet
tai ca » tai cac, tai cao, tai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: nuoc sach ((ty hang) OR (ty xang)) xa hoi. ((hieu cua) or (hieu qua)) cau doi van thanh tai ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nuoc sach ((ty hang) OR (ty xang)) xa hoi. ((hieu cua) OR (hieu qua)) cau doi van thanh tai ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "nuoc sach ((ty hang) OR (ty xang)) xa hoi. ((hieu cua) or (hieu qua)) cau doi van thanh tai ca viet".
• Adding a wildcard symbol may retrieve word variants: nuoc sach ((ty hang) OR (ty xang)) xa hoi. ((hieu cua) or (hieu qua)) cau doi van thanh tai ca viet*.