Perhaps you should try some spelling variations:
dang xay » dang van, van xay
thu sac » thu sach, thu san, thu xac
dinh vi » dinh ve, dinh viet, dinh tri
danh vi » hanh vi, danh di, danh va
cac tru » ca tru, cac tro, cac thu
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
lang xa » lang ha, lang van
sac ky » cac ky, sai ky
tru va » truc va, tu va, trung va
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky ((dang xay) or (lang xa)) hoi. hieu ve cac tru va ((danh vi) OR (dinh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky ((dang xay) OR (lang xa)) hoi. hieu ve cac tru va ((danh vi) OR (dinh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky ((dang xay) or (lang xa)) hoi. hieu ve cac tru va ((danh vi) OR (dinh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sac ky ((dang xay) or (lang xa)) hoi. hieu ve cac tru va ((danh vi) OR (dinh vi)) cua tre*.