Perhaps you should try some spelling variations:
qua thanh » quan thanh, cua thanh, qua than
thanh de » hanh de, thanh ve, thanh do
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
luu tre » luu tru, cuu tre, luy tre
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky lang xa hoi. hieu qua thanh de ((ban hanh) or (van hanh)) vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky lang xa hoi. hieu qua thanh de ((ban hanh) OR (van hanh)) vi luu tre.
• Adding a wildcard symbol may retrieve word variants: tu cac ky lang xa hoi. hieu qua thanh de ((ban hanh) or (van hanh)) vi luu tre*.