Perhaps you should try some spelling variations:
vien sach » vien bach, dien sach, viet sach
hieu vien » hieu hien, hieu viec, thieu nien
su sach » vu sach
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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