Perhaps you should try some spelling variations:
tinh dai » trinh dai, tinh da, tinh hai
te sach » toc sach
tu hang » thu hang, tu hung, ty hang
tu hanh » du hanh, lu hanh, thuc hanh
cau duc » cao duc, cau luc, chu duc
va tinh » may tinh
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
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: te sach ((tu hang) or (tu hanh)) o hoi. lieu va cau duc va tinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tu hang) OR (tu hanh)) o hoi. lieu va cau duc va tinh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ((tu hang) or (tu hanh)) o hoi. lieu va cau duc va tinh dai cua tre*.