Perhaps you should try some spelling variations:
te sach » toc sach
hanh ve » hanh vi, hanh va, hanh kem
duc van » duc va, duc tan, duc manh
cuc ban » cua ban, cac ban, cuu ban
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
ve cua » le cua, de cua, te cua
va cam » va cham, va cac, va cao
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: te sach ky nang ((x hoi) OR (o hoi)). hieu va cam ((cuc ban) or (duc van)) hanh ve 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 va cam ((cuc ban) OR (duc van)) hanh ve 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 va cam ((cuc ban) or (duc van)) hanh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((x hoi) OR (o hoi)). hieu va cam ((cuc ban) or (duc van)) hanh ve cua tre*.