Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
hieu van » thien van, lieu va, hieu ve
hanh vai » hanh vi, hanh va, hanh tai
va hanh » van hanh, va thanh, va danh
bac tuc » bac tu, bach tuoc, bac thua
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
co sach » bo sach, cuon sach, hoc sach
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa
y nang » ky nang, ly nang, v nang
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 (co sach)) y nang ma hoi. ((hieu van) or (hieu va)) bac tuc va hanh vai va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (co sach)) y nang ma hoi. ((hieu van) OR (hieu va)) bac tuc va hanh vai va trien.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (co sach)) y nang ma hoi. ((hieu van) or (hieu va)) bac tuc va hanh vai va trien*.