Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
cua tre » cua te, cuu tre, cua triet
hai cua » thai cua, dai cua, hoi cua
duc van » duc va, duc tan, duc manh
duc ban » duc tan, dua ban, duc man
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
xac ky » cac ky, bac ky
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: su ((xac ky) or (sac ky)) tang xa hoi. hieu ve cham ((duc ban) OR (duc van)) thanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((xac ky) OR (sac ky)) tang xa hoi. hieu ve cham ((duc ban) OR (duc van)) thanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((xac ky) or (sac ky)) tang xa hoi. hieu ve cham ((duc ban) OR (duc van)) thanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((xac ky) or (sac ky)) tang xa hoi. hieu ve cham ((duc ban) OR (duc van)) thanh hai cua tre*.