Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
hanh hang » thanh hang, hang hang, hanh han
cac thuc » cach thuc, cac thu, can thuc
lang van » dang van, tang van, hoang van
vien cac » vien bach, vien dai, vien da
cua tre » cua te, cua triet, dua tren
hang di » hang doi, hang vi, hang dien
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay
cuu tre » cau tren, cau treo

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((lang xa) OR (lang van)) hoi. hieu vien cac thuc hanh hang di ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((lang xa) OR (lang van)) hoi. hieu vien cac thuc hanh hang di ((cua tre) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((lang xa) OR (lang van)) hoi. hieu vien cac thuc hanh hang di ((cua tre) or (cuu tre))*.