Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
hanh tranh » canh tranh, hanh trinh, hanh trang
xuan trung » xuan truong, quang trung, doan trung
thien anh » thien danh, tien anh, thien chanh
cua trung » cua truong, cua nhung, ba trung
dan than » dan chan, ban than, van than
than tap » toan tap, han tap, phan tap

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 anh) OR (thien thanh)) - hanh tranh ((cua trung) or (xuan trung)) huong dan than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien anh) OR (thien thanh)) - hanh tranh ((cua trung) OR (xuan trung)) huong dan than tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien anh) OR (thien thanh)) - hanh tranh ((cua trung) or (xuan trung)) huong dan than tap".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien anh) OR (thien thanh)) - hanh tranh ((cua trung) or (xuan trung)) huong dan than tap*.