Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh dao » lanh dao, thanh dat, thanh dam
hanh dai » hanh tai, vanh dai, thanh dat
va triet » va thiet, va trien, ve triet
hieu va » lieu va, hieu qua
tu nang » tru nang, tu nong, tu nano
cao tuc » dao tuc, cao duc, cao suc
va cao » va cac, va co, va dao
tuc va » thuc va, truc va, tuc xa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((tu nang) or (truc nano)) xa hoi. hieu va cao tuc va ((hanh dai) OR (hanh dao)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((tu nang) OR (truc nano)) xa hoi. hieu va cao tuc va ((hanh dai) OR (hanh dao)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((tu nang) or (truc nano)) xa hoi. hieu va cao tuc va ((hanh dai) OR (hanh dao)) va triet".
• Adding a wildcard symbol may retrieve word variants: toc sach ((tu nang) or (truc nano)) xa hoi. hieu va cao tuc va ((hanh dai) OR (hanh dao)) va triet*.