Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
dinh vi » dinh ve, dinh viet, dinh tri
van lam » van nam
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua
te sai » te bai, te lai, te hai

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) or (te tai)) ky dang xay hoi. hieu van lam ((xuc va) OR (luc va)) dinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sai) OR (te tai)) ky dang xay hoi. hieu van lam ((xuc va) OR (luc va)) dinh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sai) or (te tai)) ky dang xay hoi. hieu van lam ((xuc va) OR (luc va)) dinh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sai) or (te tai)) ky dang xay hoi. hieu van lam ((xuc va) OR (luc va)) dinh vi cua tre*.