Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
nganh ky » nganh y, nganh xay, hanh ky
ban hanh » ban hang
vien dao » vien dai, vien da, vien cao
va danh » va dinh, va dan, va hanh
dao duc » giao duc, tao duoc
sanh ky » hanh ky, sang ky, thanh ky
nang xa » nang x, lang xa, nang ma
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.

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sanh ky) OR (nganh ky)) nang xa hoi. hieu vien dao duc ((ban hanh) or (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sanh ky) OR (nganh ky)) nang xa hoi. hieu vien dao duc ((ban hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sanh ky) OR (nganh ky)) nang xa hoi. hieu vien dao duc ((ban hanh) or (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: so ((sanh ky) OR (nganh ky)) nang xa hoi. hieu vien dao duc ((ban hanh) or (va danh)) vi cua tre*.