Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
su triet » su viet, su tien
cac thoi » cac toi, cac hop, cac tro
ve triet » va trien
van hanh » van thanh, ban hanh, van anh
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
cac toc » cac toi, cac nuoc
x hoi » xa hoi, o hoi, x ho

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

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