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