Perhaps you should try some spelling variations:
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
trung chan » trung phan, trung can, trung nhan
trong chan » trong chuan, trong cham, trong can
dung cong » dung trong
cong thuc » cong tac
thuc toan » thuc trang, thuat toan, thuc thanh
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 xanh) OR (chieu xanh)) - thanh ((trung chan) or (trong chan)) dung cong thuc toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu xanh)) - thanh ((trung chan) OR (trong chan)) dung cong thuc toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (chieu xanh)) - thanh ((trung chan) or (trong chan)) dung cong thuc toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (chieu xanh)) - thanh ((trung chan) or (trong chan)) dung cong thuc toan cao*.