Perhaps you should try some spelling variations:
tren nano » trien nang, tren nen, truc nano
tren mang » tren trang, tran manh, tren may
hieu van » hieu va, thien van, lieu va
va triet » va trien, ve triet, cua triet
lam xuc » cam xuc, lam duoc
kinh tu » kinh te, tinh tu, dinh tu
va kinh » va tinh, qua kinh
te sach » toc sach
van lam » van nam
xuc va » duc va, tuc va, luc va
x hoi » xa hoi, o hoi, x ho
thiet » thieu

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 ((tren nano) OR (tren mang)) x hoi. hieu van lam xuc va kinh tu ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tren nano) OR (tren mang)) x hoi. hieu van lam xuc va kinh tu ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((tren nano) OR (tren mang)) x hoi. hieu van lam xuc va kinh tu ((va triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: te sach ((tren nano) OR (tren mang)) x hoi. hieu van lam xuc va kinh tu ((va triet) or (va thiet))*.