Perhaps you should try some spelling variations:
dang xay » dang van, van xay
te sach » toc sach
hanh di » hanh vi, hanh de, hang di
thuc va » thuc vat, thuc dan, thuc day
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
lang xa » lang ha, lang van
cua tre » cua te, cuu tre, cua triet
tuc va » truc va, tuc xa, duc va
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach tu ((lang xa) or (dang xay)) hoi. hieu va cac ((tuc va) OR (thuc va)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu ((lang xa) OR (dang xay)) hoi. hieu va cac ((tuc va) OR (thuc va)) hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu ((lang xa) or (dang xay)) hoi. hieu va cac ((tuc va) OR (thuc va)) hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach tu ((lang xa) or (dang xay)) hoi. hieu va cac ((tuc va) OR (thuc va)) hanh di cua tre*.