Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hoc thiet » hoc thieu, hoc thuyet, hoc hien
thiet hai » thiet bi, thi hai, thien tai
dang cong » dung cong
bang cong » bang song, hang cong, dung cong
manh toan » thanh toan, anh tuan, tinh toan
trinh va » trinh van, trinh vat, trinh ve
san toan » van toan, dan toan, xuan toan

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 trinh va ((dang cong) or (bang cong)) ((san toan) or (manh toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hai - hanh trinh va ((dang cong) OR (bang cong)) ((san toan) OR (manh toan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hai - hanh trinh va ((dang cong) or (bang cong)) ((san toan) or (manh toan)) cao*.