Perhaps you should try some spelling variations:
khanh than » khanh thanh, khanh thuan, khan than
than cua » nhan cua, thai cua, ban cua
te sach » toc sach
duc van » duc va, duc tan, duc manh
xuc van » luc van, vuc van, xuc ban
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
co hoi » co hoc, co loi
o hai » co hai, so hai, o lai

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 ((co hoi) or (o hai)). hieu ve cac ((xuc van) OR (duc van)) khanh than cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((co hoi) OR (o hai)). hieu ve cac ((xuc van) OR (duc van)) khanh than cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((co hoi) or (o hai)). hieu ve cac ((xuc van) OR (duc van)) khanh than cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((co hoi) or (o hai)). hieu ve cac ((xuc van) OR (duc van)) khanh than cua tre*.