Perhaps you should try some spelling variations:
te sach » toc sach
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc manh, duc phan
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
va cua » va chua, via cua, ca 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)). lieu va cau ((duc van) OR (duc tan)) hanh va cua 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 cau ((duc van) OR (duc tan)) hanh va cua 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 cau ((duc van) OR (duc tan)) hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((x hoi) or (o hoi)). lieu va cau ((duc van) OR (duc tan)) hanh va cua tre*.