Perhaps you should try some spelling variations:
dua tren » dung tren
ban hanh » ban hang
cuu tre » cua tre, cau tren, cau treo
luc ban » duc ban, cuc ban, luc bat
hanh de » hanh ve, hanh kem
cau luc » cau truc, cau phuc
hieu ke » hieu kem, chieu ke, hieu ky
ky lang » ky dang, ky tang, tay lang
ke cau » ket cau
te sai » te tai, te bai, te lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sai ((ky lang) OR (ky nang)) xa hoi. hieu ke cau luc ban hanh de ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sai ((ky lang) OR (ky nang)) xa hoi. hieu ke cau luc ban hanh de ((dua tren) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sai ((ky lang) OR (ky nang)) xa hoi. hieu ke cau luc ban hanh de ((dua tren) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: te sai ((ky lang) OR (ky nang)) xa hoi. hieu ke cau luc ban hanh de ((dua tren) or (cuu tre))*.