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

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) OR (van thanh)) vi ve 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) OR (van thanh)) vi ve triet~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) nang xa hoi. hieu vien cac hoc ((van hanh) OR (van thanh)) vi ve triet*.