Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
thiet hach » thien hach, thuyet hach, thiet hai
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hanh mang » nhanh mang, hanh trang, nhanh lang
dung cong » dung trong
mang cua » manh cua, dung cua, ban cua
bai toan » bai tap
toan ban » van ban

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