Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cach hoc » cach thuc, cach thoi, dich hoc
van hanh » van thanh, ban hanh, van anh
ve triet » va trien, su triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cac hoc » cac hop, cac toc, cao hoc
bac hoc » bai hoc, bac 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 nang xa hoi. hieu vien ((((cac hoc) OR (cach hoc))) or (bac hoc)) van hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. hieu vien ((((cac hoc) OR (cach hoc))) OR (bac hoc)) van hanh vi ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. hieu vien ((((cac hoc) OR (cach hoc))) or (bac hoc)) van hanh vi ve triet".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu vien ((((cac hoc) OR (cach hoc))) or (bac hoc)) van hanh vi ve triet*.