Perhaps you should try some spelling variations:
thai lon » thai long, thai son, thai loi
van hanh » van thanh, ban hanh, van anh
lang xa » dang xay, lang van
lang ha » long ha
hieu va » lieu va, hieu qua
va thai » van thai, va tai, va tham
va hanh » va thanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
te cac » tu cac, ve cac, te cao
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te cac ky ((lang xa) OR (lang ha)) hoi. hieu va thai lon ((va hanh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te cac ky ((lang xa) OR (lang ha)) hoi. hieu va thai lon ((va hanh) OR (van hanh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cac ky ((lang xa) OR (lang ha)) hoi. hieu va thai lon ((va hanh) or (van hanh)) vi cua tre*".