Perhaps you should try some spelling variations:
thuat sach » thuat san
thuat lanh » thuat lap, thuat san
hang tai » hang va, dung tai
tai cua » thai cua, tai cuc, tri cua
va hang » van hang, va nang, va lang
lo nang » ho nang, ly nang, loai nang
cua tre » cua te, cuu tre, cua triet
le cau » ke cau, le mau, le cap
va cau » van cau, va cac, va dau
nang o » nang co, nang ho, nang ro
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: ((thuat sach) OR (thuat lanh)) lo nang o hoi. hieu ((le cau) or (va cau)) duc va hang tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuat sach) OR (thuat lanh)) lo nang o hoi. hieu ((le cau) OR (va cau)) duc va hang tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuat sach) OR (thuat lanh)) lo nang o hoi. hieu ((le cau) or (va cau)) duc va hang tai cua tre*".