Perhaps you should try some spelling variations:
tai khoa » da khoa, noi khoa
van hanh » van thanh, ban hanh, van anh
xuc van » duc van, luc van, vuc van
va chat » van chat, va phat, hoa chat
dang ha » dong ha, dung ha, tang ha
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
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: tu tai khoa ((dang ha) or (lang ha)) hoi. hieu ((va chat) OR (cao chat)) xuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu tai khoa ((dang ha) OR (lang ha)) hoi. hieu ((va chat) OR (cao chat)) xuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu tai khoa ((dang ha) or (lang ha)) hoi. hieu ((va chat) OR (cao chat)) xuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu tai khoa ((dang ha) or (lang ha)) hoi. hieu ((va chat) OR (cao chat)) xuc van hanh vi cua tre*.