Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
vanh dai » van dai, vanh tai, lanh dao
hanh dai » hanh tai, hanh dao, thanh dat
tru nang » tra nang, tri nang, truc nano
cao tuc » dao tuc, cao duc, cao suc
te sach » toc sach
hieu va » lieu va, hieu qua
tu nong » tu dong, tu cong, tu tong
tuc va » thuc va, truc va, tuc xa
va cao » va cac, va co, va dao

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 nong) or (tru nang)) xa hoi. hieu va cao tuc va ((hanh dai) or (vanh dai)) va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tu nong) OR (tru nang)) xa hoi. hieu va cao tuc va ((hanh dai) OR (vanh dai)) va trien.
• Adding a wildcard symbol may retrieve word variants: te sach ((tu nong) or (tru nang)) xa hoi. hieu va cao tuc va ((hanh dai) or (vanh dai)) va trien*.