Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
manh dai » manh hai, vanh dai, manh khai
tay lang » tai lang, tay tang, tay quang
quoc ban » quoc bao, quoc lan, quoc quan
van cam » van nam, van lam, van cau
duc van » duc va, duc tan, duc manh
thi van » thi lan, thi hanh, thi nang
ty lang » ty xang, ty hang, tu lang
cua tre » cua te, cuu tre, cua triet

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 ((ty lang) or (tay lang)) xa hoi. thi van cam ((quoc ban) or (duc van)) manh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty lang) OR (tay lang)) xa hoi. thi van cam ((quoc ban) OR (duc van)) manh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty lang) or (tay lang)) xa hoi. thi van cam ((quoc ban) or (duc van)) manh dai cua tre*.