Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
su triet » su viet, su tien
ve triet » va trien
van hanh » van thanh, ban hanh, van anh
vien cac » vien bach, vien dai, vien da
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
sach ky » sac ky, sach y, sach kem
cac hoc » cach hoc, cac hop, bac hoc
hoc van » hoc dan, hoc va, hoc vat

You may be able to get more results by adjusting your search query.

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