Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
cac luc » cau luc, coc luc, cac nuoc
va hanh » va thanh, va danh, ban hanh
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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