Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
trinh vi » trinh va, trinh ve, trinh viet
va trinh » van trinh, va tinh, lap trinh
cac tac » cac toc, cac bac, cac dac
cac tuc » cac toc, cac tu, cac nuoc
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
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 ty ((nang x) OR (nang ma)) hoi. nhieu viec ((cac tuc) OR (cac tac)) va trinh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang x) or (nang ma)) hoi. nhieu viec ((cac tuc) OR (cac tac)) va trinh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang x) or (nang ma)) hoi. nhieu viec ((cac tuc) OR (cac tac)) va trinh vi cua tre*.