Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van chat » cao chat
chat soc » cham soc, chat hoc, chat doc
ky lang » ky nang, ky dang, ky tang
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
te cac » tu cac, ve cac, te cao
ha hoi » hoa hoi, ha noi, xa hoi
soc va » hoc va, loc va, doc va
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 ((ha hoi) or (hoa hoc)). hieu van chat soc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te cac ky lang ((ha hoi) OR (hoa hoc)). hieu van chat soc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te cac ky lang ((ha hoi) or (hoa hoc)). hieu van chat soc va hanh vi cua tre*.