Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
lang xa » lang ha, dang xay, lang van
va giao » van giao, va giai, va gia
va hanh » va thanh, va danh, ban hanh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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) or (sach y)) lang xa hoi. lieu va giao duc ((va hanh) OR (van hanh)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sac ky) OR (sach y)) lang xa hoi. lieu va giao duc ((va hanh) OR (van hanh)) tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sac ky) or (sach y)) lang xa hoi. lieu va giao duc ((va hanh) OR (van hanh)) tai cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sac ky) or (sach y)) lang xa hoi. lieu va giao duc ((va hanh) OR (van hanh)) tai cua tre*.