Perhaps you should try some spelling variations:
van tham » van thanh, van tuan, van chat
ky lang » ky nang, ky dang, ky tang
va tham » va cham, va thanh, va thuat
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
ha hoi » hoa hoi, xa hoi, va 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: ve cac ky lang ((ha hoi) or (ha noi)). hieu ((va tham) OR (van tham)) soc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ve cac ky lang ((ha hoi) OR (ha noi)). hieu ((va tham) OR (van tham)) soc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ve cac ky lang ((ha hoi) or (ha noi)). hieu ((va tham) OR (van tham)) soc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ve cac ky lang ((ha hoi) or (ha noi)). hieu ((va tham) OR (van tham)) soc va hanh vi cua tre*.