Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
ban nguong » tin nguong, ban huong, ban tuong
nguong dan » huong dan
hoc thiet » hoc thieu, hoc thuyet, hoc hien
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 - hanh ((tang cua) OR (mang cua)) ban nguong dan than cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet hach - hanh ((tang cua) OR (mang cua)) ban nguong dan than cau".
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - hanh ((tang cua) OR (mang cua)) ban nguong dan than cau*.