Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cua tre » cua te, cuu tre, cua triet
vuc van » duc van, luc van, thuc van
va chat » van chat, va phat, cao chat
ve chat » van chat
sai kho » dai kho, tai khoa, dai khoa
lang ha » long ha
tang ha » tang ma, trung ha, tang van
vi cua » vai cua, di cua
tu sai » tu bai, tu san, tu cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai kho ((tang ha) or (lang ha)) hoi. hieu ((ve chat) OR (va chat)) vuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai kho ((tang ha) OR (lang ha)) hoi. hieu ((ve chat) OR (va chat)) vuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai kho ((tang ha) or (lang ha)) hoi. hieu ((ve chat) OR (va chat)) vuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sai kho ((tang ha) or (lang ha)) hoi. hieu ((ve chat) OR (va chat)) vuc van hanh vi cua tre*.