Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
va triet » va thiet, ve triet, cua triet
hanh sua » hinh su, hanh va, hanh tu
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
cam loc » cam lo
y nang » ky nang, ly nang, v nang
loc va » hoc va, luc va
x hoi » xa hoi, o hoi, x ho

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 y nang x hoi. ((hieu ve) or (hieu va)) cam loc va hanh sua ((va triet) OR (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x hoi. ((hieu ve) OR (hieu va)) cam loc va hanh sua ((va triet) OR (va trien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. ((hieu ve) or (hieu va)) cam loc va hanh sua ((va triet) OR (va trien))".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. ((hieu ve) or (hieu va)) cam loc va hanh sua ((va triet) OR (va trien))*.