Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
truc va » thuc va, thuc vat, trung va
hieu va » lieu va, hieu qua
su sach » vu sach
nang ma » tang ma, sang ma, nang cao
so sach » so sanh, bo sach, co sach
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, tuc xa, duc va
y nang » ky nang, ly nang, v nang
vai va » mai va, dai va, hai va
va cam » va cham, va cac, va cao

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 cam ((tuc va) OR (truc 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 cam ((tuc va) OR (truc 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 cam ((tuc va) OR (truc va)) hanh vai va triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) y nang ma hoi. hieu va cam ((tuc va) OR (truc va)) hanh vai va triet*.