Perhaps you should try some spelling variations:
ban hanh » ban hang
te sach » toc sach
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
cam duc » cam xuc, cao duc, pham duc
duc ban » duc tan, duc van, dua ban
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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