Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
tan hanh » tan thanh, tang hanh, toan hanh
te sach » toc sach
ty nano » day nano, tao nano
tu nano » truc nano
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
di cuu » di cau, di cua, dinh cuu

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 ((ty nano) OR (tu nano)) xa hoi. ((hieu van) or (hieu va)) giao duc tan hanh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty nano) OR (tu nano)) xa hoi. ((hieu van) OR (hieu va)) giao duc tan hanh di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty nano) OR (tu nano)) xa hoi. ((hieu van) or (hieu va)) giao duc tan hanh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty nano) OR (tu nano)) xa hoi. ((hieu van) or (hieu va)) giao duc tan hanh di cuu tre*.