Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cac loc » cac lop, cac hoc, cac nuoc
cac toc » cac toi, cac nuoc, cac thoi
cua tre » cuu tre, cua triet, dua tren
tu van » tu va
cua te » cua tu

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

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