Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
viec cac » vien cac, viec cua, viec lam
trinh vi » trinh va, trinh ve, trinh viet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
xuc va » tuc va, luc va, xac va
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang x) OR (nang ma)) hoi. nhieu viec cac ((xuc va) OR (duc va)) trinh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang x) or (nang ma)) hoi. nhieu viec cac ((xuc va) OR (duc va)) trinh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang x) or (nang ma)) hoi. nhieu viec cac ((xuc va) OR (duc va)) trinh vi cua tre*.