Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
trung tuan » trung thanh, trung tam, tran tuan
hoc thieu » toc thieu, hoc hien
trung cua » truong cua, trung cap, dung cua
cong ban » cong bang, cong tan, cong dan
cong san » cong tac
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu sach - thanh ((trung cua) OR (trung tuan)) nhung ((cong ban) or (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - thanh ((trung cua) OR (trung tuan)) nhung ((cong ban) OR (cong san)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - thanh ((trung cua) OR (trung tuan)) nhung ((cong ban) or (cong san)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - thanh ((trung cua) OR (trung tuan)) nhung ((cong ban) or (cong san)) toan cau*.