Perhaps you should try some spelling variations:
thanh hoa » thanh pho
thanh hai » thanh phan, thanh san
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
cuu tre » cua tre, cau tren, cau treo
duc van » duc va, duc tan, duc manh
duc ban » duc tan, dua ban, duc man
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang

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