Perhaps you should try some spelling variations:
thien danh » thien anh, thien dang, thien thanh
canh trinh » canh tranh, hanh trinh, canh tinh
nhung cong » dung cong, thong cong, nhung don
hang cong » dang cong, hang nong, bang cong
trinh va » trinh van, trinh vat, trinh ve
dan phan » doan phan, dan chan, van phan
phan cau » phan dau, phan cac, phan tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thien danh) or (trieu tinh)) - canh trinh va ((nhung cong) OR (hang cong)) dan phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien danh) OR (trieu tinh)) - canh trinh va ((nhung cong) OR (hang cong)) dan phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien danh) or (trieu tinh)) - canh trinh va ((nhung cong) OR (hang cong)) dan phan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien danh) or (trieu tinh)) - canh trinh va ((nhung cong) OR (hang cong)) dan phan cau*.