Perhaps you should try some spelling variations:
sach tren » sach tien, sach tranh
va triet » va trien, ve triet, cua triet
te sach » toc sach
kinh tu » kinh te, tinh tu, dinh tu
va kinh » va tinh, qua kinh
lam xuc » cam xuc, lam duoc
hieu va » lieu va, hieu qua
va lam » van lam, va lap
xuc va » duc va, tuc va, luc va
nano 1 » nano o
nano x » nano o
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 x) OR (nano 1)) hoi. hieu va 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 x) OR (nano 1)) hoi. hieu va 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 x) OR (nano 1)) hoi. hieu va lam xuc va kinh tu ((va triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: te sach tren ((nano x) OR (nano 1)) hoi. hieu va lam xuc va kinh tu ((va triet) or (va thiet))*.