Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
hoc thiet » hoc thieu, hoc thuyet, hoc hien
thiet hai » thiet bi, thi hai, thien tai
hanh manh » hanh mang, lanh manh, hoang manh
dung cong » dung trong
manh cua » doanh 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 hai - hanh manh cua ((nhung cong) or (dung cong)) bai toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hai - hanh manh cua ((nhung cong) OR (dung cong)) bai toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hai - hanh manh cua ((nhung cong) or (dung cong)) bai toan ban*.