Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
duc ban » duc van, dua ban, duc man
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
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: vu ((sach ky) OR (sac ky)) nang xa hoi. hieu van cam ((duc ban) or (duc tan)) thanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach ky) OR (sac ky)) nang xa hoi. hieu van cam ((duc ban) OR (duc tan)) thanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach ky) OR (sac ky)) nang xa hoi. hieu van cam ((duc ban) or (duc tan)) thanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: vu ((sach ky) OR (sac ky)) nang xa hoi. hieu van cam ((duc ban) or (duc tan)) thanh hai cua tre*.