Perhaps you should try some spelling variations:
dung phuong » dung thuong, bang phuong, dung chung
thanh trung » thanh tung
phuong tinh » phuong trinh, phuong binh, khuong tinh
hanh trang » canh tranh, hanh trinh, minh trang
chieu sang » chieu sach, chieu xanh, hieu lang
hieu sang » hieu lang, hieu quang, nhieu tang
cua dung » cua dang, cua dong, qua dung
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) or (chieu sang)) - ((hanh trang) OR (thanh trung)) cua dung phuong tinh toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (chieu sang)) - ((hanh trang) OR (thanh trung)) cua dung phuong tinh toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) or (chieu sang)) - ((hanh trang) OR (thanh trung)) cua dung phuong tinh toan tap".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (chieu sang)) - ((hanh trang) OR (thanh trung)) cua dung phuong tinh toan tap*.