Perhaps you should try some spelling variations:
te sach » toc sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
luc ban » cuc ban, luc bat, luc van
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
vi cua » vai cua, di cua
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)). hieu ve cam ((luc ban) or (duc ban)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((x hoi) OR (o hoi)). hieu ve cam ((luc ban) OR (duc ban)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((x hoi) OR (o hoi)). hieu ve cam ((luc ban) or (duc ban)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((x hoi) OR (o hoi)). hieu ve cam ((luc ban) or (duc ban)) hanh vi cua tre*.