Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu vien » hieu viec, thieu nien, hieu tieng
cac ban » cac dan, cac van, can ban
cac bac » cac bai, cac cach, sach bac
sach ky » sac ky, sach y, sach ty
te sach » toc sach
cuu tre » cua tre, cau tren, cau treo
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi cuu » vi luu, vinh cuu
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: te sach ky nang x hoi. ((hieu vien) or (hieu hien)) ((cac bac) OR (cac ban)) va dan vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang x hoi. ((hieu vien) OR (hieu hien)) ((cac bac) OR (cac ban)) va dan vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang x hoi. ((hieu vien) or (hieu hien)) ((cac bac) OR (cac ban)) va dan vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang x hoi. ((hieu vien) or (hieu hien)) ((cac bac) OR (cac ban)) va dan vi cuu tre*.