Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
cong toan » cong hoan, cong tuan, cong doan
nhanh cay » nhanh ha, nhanh va, hanh cac
nhanh bac » nhanh ha, nhanh va
cong cac » cuong cac, cong tac, cong cau
cac dung » cach dung, cac duong, tac dung
cong tan » cong tac, cong san, cong thanh

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 - thanh cong cac dung ((cong toan) OR (cong tan)) ((nhanh cay) or (nhanh bac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - thanh cong cac dung ((cong toan) OR (cong tan)) ((nhanh cay) OR (nhanh bac)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc thieu sach - thanh cong cac dung ((cong toan) OR (cong tan)) ((nhanh cay) or (nhanh bac))".
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - thanh cong cac dung ((cong toan) OR (cong tan)) ((nhanh cay) or (nhanh bac))*.