Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
chat duc » chat xuc, chat doc, chet duoc
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
duc van » duc va, duc tan, duc manh
su sach » so sach, vu sach
hieu ve » hieu van
tu nong » tu dong, tu cong, tu tong
tu nang » tru nang, tu nano, tu lang
va va » va van, va vua, va vai

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

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