Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
cong thanh » dong thanh, cong trinh, cong tan
thanh phan » thanh pho, thanh san, thanh toan
hieu cach » hieu cac, chieu sach, hieu ca
trung dai » truong dai, truong dao, trung cap
dung cong » dung trong
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) OR (hieu cach)) - thanh ((trung dai) or (trung tam)) dung cong thanh phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((thieu sach) OR (hieu cach)) - thanh ((trung dai) OR (trung tam)) dung cong thanh phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((thieu sach) OR (hieu cach)) - thanh ((trung dai) or (trung tam)) dung cong thanh phan cau".
• Adding a wildcard symbol may retrieve word variants: toc ((thieu sach) OR (hieu cach)) - thanh ((trung dai) or (trung tam)) dung cong thanh phan cau*.