Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
viec cac » vien cac, viec cua, viec lam
hanh vai » hanh vi, hanh va, hanh tai
vai cuu » vai cua
cao van » cac van, dao van, cao dang
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cuu tre » cua tre, cau tren, cau treo
co van » vo van, so van, do van

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu viec cac ((co van) or (cao van)) hanh vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu viec cac ((co van) OR (cao van)) hanh vai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) OR (nang ma)) hoi. hieu viec cac ((co van) or (cao van)) hanh vai cuu tre*".