Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
toc sach » hoc sach, doc sach, thuoc sach
su sach » so sach, vu sach
dai cuu » dai cua, dai huu
cuc ban » cac ban, cuu ban, duc ban
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
va cam » va cham, va cac, va cao
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: ((su sach) or (toc sach)) ky nang o hoi. hieu va cam ((cuc ban) or (cua ban)) thanh dai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky nang o hoi. hieu va cam ((cuc ban) OR (cua ban)) thanh dai cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (toc sach)) ky nang o hoi. hieu va cam ((cuc ban) or (cua ban)) thanh dai cuu tre*.