Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
thuc dan » thuc hanh, hoc dan, thuc vat
thuc day » thuc vat
sach tu » sach thu, cach tu, sach ty
hai cua » thai cua, dai cua, hoi cua
te sach » toc sach
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
tu nang » tru nang, tu nong, tu nano
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: te sach tu nang xa hoi. ((hieu va) or (lieu va)) can ((thuc day) OR (thuc dan)) hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nang xa hoi. ((hieu va) OR (lieu va)) can ((thuc day) OR (thuc dan)) hanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu nang xa hoi. ((hieu va) or (lieu va)) can ((thuc day) OR (thuc dan)) hanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach tu nang xa hoi. ((hieu va) or (lieu va)) can ((thuc day) OR (thuc dan)) hanh hai cua tre*.