Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
te sach » toc sach
sach ky » sac ky, sach y, sach ty
cac tac » cac toc, cac bac, cac dac
va nang » van nang, da nang, cam nang
nang di » nang du, hang di, nang ji
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, ma hoa, me hoi
tac va » tac da, tac xa, tuc va
di cua » dai cua, doi cua, de cua

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 ((ma hoi) OR (xa hoi)). hieu vien cac tac va nang di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((ma hoi) OR (xa hoi)). hieu vien cac tac va nang di cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((ma hoi) OR (xa hoi)). hieu vien cac tac va nang di cua tre*.