Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
cao khoa » lao khoa, bao khoa, cac khoa
viec cac » vien cac, viec cua, viec lam
hang doi » hang di, hang loi, huong doi
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cao hoa » cao hoat, cau hoa, cao hoc
cac thu » cach thuc, cac thoi
va hang » van hang, va nang, va lang
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
thu va » thuc va, thue va, tu 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 ky nang ((cao hoa) or (cao khoa)). hieu viec cac thu va hang doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((cao hoa) OR (cao khoa)). hieu viec cac thu va hang doi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((cao hoa) or (cao khoa)). hieu viec cac thu va hang doi cua tre*.