Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
cau tren » cu tren, dau tren, ca tren
van hanh » van thanh, ban hanh, van anh
hien cac » thien cac, vien cac, hieu cac
va hanh » va thanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
so bang » so dang, so lang, co bang
bang ky » dang ky, ban ky, tang ky
cac dac » cac dan, cac dai, cac bac
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang

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

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