Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, ve triet, cua triet
hanh lam » thanh lap, hanh kem, hanh va
chat luc » chat xuc, chat lua, nhan luc
hieu van » thien van, lieu va, hieu ve
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
luc van » luoc van, luu van, duc van
ty nang » ky nang, ty xang, ty hang
su sach » so sach, vu sach
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 ty nang x hoi. ((hieu van) or (hieu va)) chat luc van hanh lam ((va triet) OR (va trien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang x hoi. ((hieu van) OR (hieu va)) chat luc van hanh lam ((va triet) OR (va trien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang x hoi. ((hieu van) or (hieu va)) chat luc van hanh lam ((va triet) OR (va trien))".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang x hoi. ((hieu van) or (hieu va)) chat luc van hanh lam ((va triet) OR (va trien))*.