Perhaps you should try some spelling variations:
thai son » thai den, thai do, thai hoc
van hanh » van thanh, ban hanh, van anh
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
hieu va » lieu va
son van » song van, san van, son va
cua tre » cua te, cuu tre, cua triet
te sac » te sach, te cac, te san
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 sac ((ky lang) OR (ky dang)) xa hoi. ((hieu va) or (hieu qua)) thai son van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ((ky lang) OR (ky dang)) xa hoi. ((hieu va) OR (hieu qua)) thai son van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ((ky lang) OR (ky dang)) xa hoi. ((hieu va) or (hieu qua)) thai son van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sac ((ky lang) OR (ky dang)) xa hoi. ((hieu va) or (hieu qua)) thai son van hanh vi cua tre*.