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
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
hang xa » hoang xa, hang va, hang ca
cau doi » cau hoi, cau do, cau noi
doi van » do van, doi va, doi ban
ca viet » va viet, hoa viet, san viet
co viet » so viet, o viet, hoc viet

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