Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
danh vai » danh sai, danh va, doanh van
sach doi » sach moi, sach dao, sach bai
sach hoi » sach moi, cach thoi, hoach hoi
cau duc » cao duc, cau luc, chu duc
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach hoi) or (sach doi)) lang xa hoi. ((hieu van) or (hieu va)) cau duc va danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach hoi) OR (sach doi)) lang xa hoi. ((hieu van) OR (hieu va)) cau duc va danh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach hoi) or (sach doi)) lang xa hoi. ((hieu van) or (hieu va)) cau duc va danh vai cua tre*.