Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, chiet tach
thiet hai » thiet bi, thi hai, thien tai
ban huong » bang phuong, ban hang, anh huong
tang cua » hang cua, tang luan, thong cua
mang cua » manh cua, dung cua, ban cua
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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 (thiet hai)) - hanh ((tang cua) or (mang cua)) ban huong dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet hach) OR (thiet hai)) - hanh ((tang cua) OR (mang cua)) ban huong dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet hach) OR (thiet hai)) - hanh ((tang cua) or (mang cua)) ban huong dan than cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet hach) OR (thiet hai)) - hanh ((tang cua) or (mang cua)) ban huong dan than cau*.