Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » thien van, lieu va, hieu ve
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
duc ban » duc tan, duc van, dua ban
hai cuu » hai cua, hai chu, hai cuc
cuu tre » cua tre, cau tren, cau treo

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