Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
chieu sach » chinh sach, chiet tach, chieu sang
hanh manh » hanh mang, hoang manh, thanh minh
lanh manh » lanh tranh, lan anh, van manh
hach toan » thanh toan, manh toan
ho chieu » theo chieu, hoc thieu, doi chieu
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: ho chieu sach - ((hanh manh) or (lanh manh)) va nhung cong ((tac toan) or (hach toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu sach - ((hanh manh) OR (lanh manh)) va nhung cong ((tac toan) OR (hach toan)) cau.
• Adding a wildcard symbol may retrieve word variants: ho chieu sach - ((hanh manh) or (lanh manh)) va nhung cong ((tac toan) or (hach toan)) cau*.