Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
thong cong » trong cong, tong cong, thong thong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trang cua » tranh cua, tang cua, trung cua
dung cong » dung trong
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap
ban cua » ban quan

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 ((trang cua) or (ban cua)) ((thong cong) or (dung cong)) dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - hanh ((trang cua) OR (ban cua)) ((thong cong) OR (dung cong)) dan than cau.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - hanh ((trang cua) or (ban cua)) ((thong cong) or (dung cong)) dan than cau*.