Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
cong manh » cong danh, duong manh, cong thanh
manh toan » thanh toan, anh tuan, tinh toan
so thiet » soc thiet, hoa thiet, tao thiet
ban quan » van quan
toan cau » toan cao, toan ban, toan tap

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thiet) OR (so thiet)) tach - anh ((ban cua) OR (ban quan)) nhung cong manh toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thiet) or (so thiet)) tach - anh ((ban cua) OR (ban quan)) nhung cong manh toan cau~".
• Adding a wildcard symbol may retrieve word variants: ((hoc thiet) or (so thiet)) tach - anh ((ban cua) OR (ban quan)) nhung cong manh toan cau*.