Perhaps you should try some spelling variations:
ve triet » va trien, su triet
van hanh » van thanh, ban hanh, van anh
cac truc » cau truc, cac tru, cac trung
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
so sach » so sanh, bo sach, co sach
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
sach v » sach va, sach y, sach 2
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang
vi ve » va ve, gi ve, ve ve

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

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