Perhaps you should try some spelling variations:
nhung cau » chung cu, nhung bai, nhu cau
thu nhung » thuc nhung, thi nhung, tu nhung
sua triet » su triet, cua triet, sua tiet
thu sach » thuat sach, thuoc sach, thu hoach
hanh tai » thanh tai, hang tai, han tai
tu sach » su sach, te sach, tu cach
hieu ca » hieu cac, hieu cua, hieu va
ca chat » cao chat, cac chat, va chat
thai va » thai van
va hanh » van hanh, va thanh, ban hanh
tai sua » dai sua, tai su, tai cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) thu nhung cau hoi. hieu ca chat thai va hanh tai sua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) thu nhung cau hoi. hieu ca chat thai va hanh tai sua triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) thu nhung cau hoi. hieu ca chat thai va hanh tai sua triet*.