Perhaps you should try some spelling variations:
khong cong » thong cong, khong cang, chong 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
ho thiet » hoa thiet, so thiet, hoc thieu
tung tam » trung tam, vung tam, tuong tac
dung tam » duong tam, dung tai, dung lam
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho thiet) or (hoc thiet)) tach - manh ((tung tam) OR (dung tam)) khong cong manh toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho thiet) OR (hoc thiet)) tach - manh ((tung tam) OR (dung tam)) khong cong manh toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho thiet) or (hoc thiet)) tach - manh ((tung tam) OR (dung tam)) khong cong manh toan cao".
• Adding a wildcard symbol may retrieve word variants: ((ho thiet) or (hoc thiet)) tach - manh ((tung tam) OR (dung tam)) khong cong manh toan cao*.