Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
ve triet » va trien, su triet
sach ky » sach y, sach ty, sach kem
toc van » toc san, tac van, oc van
hoc van » hoc dan, hoc va, hoc vat
sac ky » cac ky, sai ky
x hoi » xa hoi, o hoi, x ho
vi ve » va ve, gi ve, ve ve

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