Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
duc ban » duc tan, dua ban, duc man
hai cua » thai cua, dai cua, hoi cua
duc van » duc va, duc tan, duc manh
van cam » van nam, van lam, van cau
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet

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

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