Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cau tren » dau tren, ca tren, cau treo
hieu van » hieu va, thien van, lieu va
thanh va » thanh van, hanh va, thanh ha
sach ty » sach y, sach tu, sach thu
cuu tre » cua tre, cau treo
te sach » toc sach
duc ban » duc tan, duc van, dua ban
bao duc » dao duc, bao luc, cao duc
van bao » van ban, van dao
ty nang » ky nang, ty xang, ty hang
cu tren » tu tren, dua tren
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty nang x hoi. hieu van bao duc ban thanh va ((cuu tre) or (((cau tren) or (cu tren))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang x hoi. hieu van bao duc ban thanh va ((cuu tre) OR (((cau tren) OR (cu tren)))).
• Adding a wildcard symbol may retrieve word variants: te sach ty nang x hoi. hieu van bao duc ban thanh va ((cuu tre) or (((cau tren) or (cu tren))))*.