Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
so sach » so sanh, bo sach, co sach
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
te sach » toc sach
nang o » nang co, nang ho, nang ro
luc va » duc va, tuc va, loc va
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: ((so sach) or (te sach)) ky nang o hoi. ((hieu ve) or (hieu va)) cau luc va hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (te sach)) ky nang o hoi. ((hieu ve) OR (hieu va)) cau luc va hanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (te sach)) ky nang o hoi. ((hieu ve) or (hieu va)) cau luc va hanh tai cua tre*.