Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va
su sach » vu sach
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
y nang » ky nang, ly nang, v nang
tuc va » thuc va, truc va, tuc xa
vai va » mai va, dai va, hai va

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