Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu vien » hieu viec, thieu nien, hieu tieng
van hanh » van thanh, ban hanh, van anh
cac cao » ca cao, bac cao, cac cam
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
cac co » cac cong
vi cua » vai cua, di cua
cua te » cua tu
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: tu sach ky nang x hoi. ((hieu vien) or (hieu hien)) ((cac cao) OR (cac co)) van hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu vien) OR (hieu hien)) ((cac cao) OR (cac co)) van hanh vi cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu vien) or (hieu hien)) ((cac cao) OR (cac co)) van hanh vi cua te*".