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