Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
toan thang » toan thong, thanh thang, tran thanh
thang cong » thanh cong, thang long, thong cong
canh tinh » hanh tinh, manh tinh, nhanh tinh
cong tan » cong tac, cong san, cong thanh
tan phan » toan phan, than phan, van phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc thieu sach - ((canh tranh) or (canh tinh)) toan thang cong tan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - ((canh tranh) OR (canh tinh)) toan thang cong tan phan tu.
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - ((canh tranh) or (canh tinh)) toan thang cong tan phan tu*.