Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thai cua » than cua, tai cuc, tri cua
van hanh » ban hanh, van anh, van ban
dang xay » dang van, van xay
cua tre » cua te, cuu tre, cua triet
cao duc » dao duc, cao suc, giao duc
hieu ve » hieu va, hieu van
dang xa » lang xa, dang ha, dang va
ve cao » va cao, ve bao, ve cac
sai ky » sac ky
su sai » su tai, su hai, su dai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky ((dang xa) or (dang xay)) hoi. hieu ve cao duc ((van hanh) OR (van thanh)) thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky ((dang xa) OR (dang xay)) hoi. hieu ve cao duc ((van hanh) OR (van thanh)) thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky ((dang xa) or (dang xay)) hoi. hieu ve cao duc ((van hanh) OR (van thanh)) thai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sai ky ((dang xa) or (dang xay)) hoi. hieu ve cao duc ((van hanh) OR (van thanh)) thai cua tre*.