Perhaps you should try some spelling variations:
thanh phan » thanh pho, thanh san, thanh toan
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
lam duc » lam duoc, pham duc, nam duoc
cua tre » cua te, cua triet, dua tren
duc ban » duc tan, duc van, dua ban
van lam » van nam
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cuu tre » cau tren, cau treo
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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