Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cau treo » cau theo, cau triet, cau trieu
hanh vai » hanh vi, hanh va, hanh tai
va hanh » van hanh, va thanh, va danh
cao tuc » dao tuc, cao duc, cao suc
te sach » toc sach
hieu va » lieu va, hieu qua
tu nano » truc nano
tu nang » tru nang, tu nong, tu lang
tuc va » thuc va, truc va, tuc xa
va cao » va cac, va co, va dao
x hoi » xa hoi, o hoi, x ho

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) or (tu nano)) x hoi. hieu va cao tuc va hanh vai ((cau treo) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tu nang) OR (tu nano)) x hoi. hieu va cao tuc va hanh vai ((cau treo) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((tu nang) or (tu nano)) x hoi. hieu va cao tuc va hanh vai ((cau treo) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: te sach ((tu nang) or (tu nano)) x hoi. hieu va cao tuc va hanh vai ((cau treo) OR (cau tren))*.