Perhaps you should try some spelling variations:
dang xay » dang van, van xay
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

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 sac ky ((nang ma) OR (dang xay)) hoi. ((hieu va) OR (hieu qua)) cau truc va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky ((nang ma) or (dang xay)) hoi. ((hieu va) OR (hieu qua)) cau truc va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky ((nang ma) or (dang xay)) hoi. ((hieu va) OR (hieu qua)) cau truc va hanh vi cua tre*.