Perhaps you should try some spelling variations:
phuong cong » phuong dong, phong cong, phung cong
theo chieu » theo tieu, ho chieu, theo chu
chieu xanh » chieu sach, chieu sang, chieu tinh
hanh tang » hanh trang, anh tang, hanh mang
va phuong » va thuong, cac phuong
tac toan » tam toan, hach toan, tich toan
tap toan » tap doan, tap quan, bai toan
tang va » trang va, tang van, thang va

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu xanh - hanh tang va phuong cong ((tac toan) OR (tap toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu xanh - hanh tang va phuong cong ((tac toan) OR (tap toan)) cau".
• Adding a wildcard symbol may retrieve word variants: theo chieu xanh - hanh tang va phuong cong ((tac toan) OR (tap toan)) cau*.