Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dang xa » dang xay, lang xa, dang ha
sach ky » sac ky, sach ty, sach kem
cac tuc » cac toc, cac tu, cac tac
van anh » van thanh, tuan anh, van minh
anh vai » anh va, anh bai, anh van
vai va » mai va, dai va, hai va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) OR (sach y)) dang xa hoi. hieu vien ((cac tuc) or (cac nuoc)) van anh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach y)) dang xa hoi. hieu vien ((cac tuc) OR (cac nuoc)) van anh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sach y)) dang xa hoi. hieu vien ((cac tuc) or (cac nuoc)) van anh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sach y)) dang xa hoi. hieu vien ((cac tuc) or (cac nuoc)) van anh vai va thiet*.