Perhaps you should try some spelling variations:
dung phuong » dung thuong, bang phuong, dung chung
trung tuan » trung thanh, trung tam, truong thanh
cong huong » cong thuong, cong luong, cong hung
hieu sang » chieu sang, hieu lang, hieu quang
tran tuan » tran xuan, tran quang, tran thanh
doc hieu » toc thieu, hoc thieu, hoc hien
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sang - hanh ((trung tuan) OR (tran tuan)) ((dung phuong) or (cong huong)) tinh toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - hanh ((trung tuan) OR (tran tuan)) ((dung phuong) OR (cong huong)) tinh toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sang - hanh ((trung tuan) OR (tran tuan)) ((dung phuong) or (cong huong)) tinh toan tap".
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - hanh ((trung tuan) OR (tran tuan)) ((dung phuong) or (cong huong)) tinh toan tap*.