Perhaps you should try some spelling variations:
phuong cong » phuong dong, phong cong, phuong hoang
dung doanh » dung dan, dung dong
phung cong » nhung cong, phong cong, nhung chong
van nguyen » toan nguyen, tran nguyen, xuan nguyen
nguyen tap » nguyen tac, nguyen tan, nguyen tat
hoc thieu » toc thieu, hoc hien
doanh cua » doanh luan
ho chieu » theo chieu, doi chieu, mot chieu

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) OR (hoc thieu)) tinh - dung doanh cua ((phuong cong) or (phung cong)) van nguyen tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) tinh - dung doanh cua ((phuong cong) OR (phung cong)) van nguyen tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (hoc thieu)) tinh - dung doanh cua ((phuong cong) or (phung cong)) van nguyen tap".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (hoc thieu)) tinh - dung doanh cua ((phuong cong) or (phung cong)) van nguyen tap*.