Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
canh trinh » canh tranh, hanh trinh, anh trinh
canh tinh » hanh tinh, manh tinh, canh tranh
toan dang » tran dang, toan mang, toan tang
dang cong » dung cong
cong toan » cong tan, cong hoan, cong tuan
toan phan » thanh phan, toan ban, hoa phan
phan cau » phan dau, phan cac, phan tu

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 trinh) or (canh tinh)) toan dang cong toan phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - ((canh trinh) OR (canh tinh)) toan dang cong toan phan cau.
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - ((canh trinh) or (canh tinh)) toan dang cong toan phan cau*.