Perhaps you should try some spelling variations:
khanh tri » khanh tra, thanh tri, khach trai
tan khanh » tran khanh, van khanh, dan khanh
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
ve cac » vien cac
cua te » cua tu
o hoi » co hoi, o hoc, o hoa
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: thu sach ky nang ((o hoi) or (o hai)). hieu ((ve cac) OR (va cac)) duc tan khanh tri cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((o hoi) OR (o hai)). hieu ((ve cac) OR (va cac)) duc tan khanh tri cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((o hoi) or (o hai)). hieu ((ve cac) OR (va cac)) duc tan khanh tri cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((o hoi) or (o hai)). hieu ((ve cac) OR (va cac)) duc tan khanh tri cua te*.