Perhaps you should try some spelling variations:
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
cac loc » cac lop, cac hoc, cac nuoc
hieu va » lieu va, hieu qua
xay hoi » xa hoi, tay hoi, cay phoi
ky danh » ky anh
ky dang » ky nang
vi cua » vai cua, di cua
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ((ky dang) or (ky danh)) xay hoi. hieu va ((cac loc) OR (cac toc)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ((ky dang) OR (ky danh)) xay hoi. hieu va ((cac loc) OR (cac toc)) va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ((ky dang) or (ky danh)) xay hoi. hieu va ((cac loc) OR (cac toc)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ((ky dang) or (ky danh)) xay hoi. hieu va ((cac loc) OR (cac toc)) va hanh vi cua tre*.