Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
danh sai » dung sai, danh bat, danh dau
danh vai » danh va, doanh van, dang van
tu sach » thu sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
su sach » so sach, vu sach
cac lo » cac lop, cac co, cac bo
lo va » lo van, lao va, ly va

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) or (su sach)) ky nang xa hoi. hieu vien cac lo va ((danh vai) OR (danh sai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang xa hoi. hieu vien cac lo va ((danh vai) OR (danh sai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang xa hoi. hieu vien cac lo va ((danh vai) OR (danh sai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang xa hoi. hieu vien cac lo va ((danh vai) OR (danh sai)) cua tre*.