Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham cuu » cap cuu, chat cua
cua tre » cua te, cuu tre, cua triet
tai cua » thai cua, tai cuc, tri cua
va hanh » va thanh, va danh, ban hanh
va cham » va chat, va tham
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
te bai » te bao, te tai, te ban
te sai » te tai, te lai, te hai

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

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