Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, thanh dat
vanh dai » van dai, vanh tai, lanh dao
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
chuc va » thuc vat
cua tre » cua te, cuu tre, cua triet
y hang » ly hang, ty hang, yu hang
va hoa » van hoa, va hoc, ma hoa
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach y hang va hoa. hieu ve cau ((thuc va) or (chuc va)) ((hanh dai) OR (vanh dai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach y hang va hoa. hieu ve cau ((thuc va) OR (chuc va)) ((hanh dai) OR (vanh dai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach y hang va hoa. hieu ve cau ((thuc va) or (chuc va)) ((hanh dai) OR (vanh dai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: co sach y hang va hoa. hieu ve cau ((thuc va) or (chuc va)) ((hanh dai) OR (vanh dai)) cua tre*.