Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
cac tac » cac toc, cac bac, cac dac
van anh » van thanh, tuan anh, van minh
anh vai » anh va, anh bai, anh van
sac ky » cac ky, sai ky
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: tu ((sach ky) OR (sac ky)) nang xa hoi. hieu vien ((cac tac) or (dat nuoc)) van anh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang xa hoi. hieu vien ((cac tac) OR (dat nuoc)) van anh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sac ky)) nang xa hoi. hieu vien ((cac tac) or (dat nuoc)) van anh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sac ky)) nang xa hoi. hieu vien ((cac tac) or (dat nuoc)) van anh vai va thiet*.