Perhaps you should try some spelling variations:
thiet hach » thuyet hach, thiet hai, chiet tach
thien hach » thien thanh, hien hanh
hanh tranh » canh tranh, hanh trinh, hanh trang
huong manh » duong manh, hung manh, luong manh
phuong anh » phuong hoang
tranh cua » doanh cua, manh cua
cua nhung » va nhung

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thiet hach) OR (thien hach)) - hanh tranh cua nhung ((huong manh) or (phuong anh)) van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet hach) OR (thien hach)) - hanh tranh cua nhung ((huong manh) OR (phuong anh)) van ban*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet hach) OR (thien hach)) - hanh tranh cua nhung ((huong manh) or (phuong anh)) van ban*".