Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
chieu sang » chieu sach, chieu xanh, hieu lang
hoc chieu » hoc thieu, ho chieu, hoc hien
canh manh » lanh manh, cach mang, van manh
cua nhung » va nhung
hach toan » thanh toan, manh toan
tac toan » tap toan, tam toan, tich toan

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

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