Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
sach thu » sach thue, sach thieu, sach tham
va thanh » gia thanh, ban thanh, va tinh
van cua » vang cua, ban cua, dan cua
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sach uu » sach luu, sach tu, sach xu
ha hoi » hoa hoi, ha noi, va hoi
ve cap » ve cac, le cap, ve cai
cuu va » cuu van, cuu ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach uu) or (sach thu)) lang ((ha hoi) OR (xa hoi)). hieu ve cap cuu va thanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach uu) OR (sach thu)) lang ((ha hoi) OR (xa hoi)). hieu ve cap cuu va thanh van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach uu) or (sach thu)) lang ((ha hoi) OR (xa hoi)). hieu ve cap cuu va thanh van cua tre".
• Adding a wildcard symbol may retrieve word variants: so ((sach uu) or (sach thu)) lang ((ha hoi) OR (xa hoi)). hieu ve cap cuu va thanh van cua tre*.