Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
trung tuan » trung thanh, trung tam, tran tuan
hoc thieu » toc thieu, hoc hien
trung cua » truong cua, trung cap, dung cua
dung cong » dung trong
tac toan » tap toan, hach toan, tich toan
tam toan » tap toan, tam than, pham toan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - thanh ((trung cua) OR (trung tuan)) dung cong ((tac toan) OR (tam toan)) tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - thanh ((trung cua) or (trung tuan)) dung cong ((tac toan) OR (tam toan)) tap~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - thanh ((trung cua) or (trung tuan)) dung cong ((tac toan) OR (tam toan)) tap*.