Perhaps you should try some spelling variations:
hoc thiet » hoc thieu, hoc thuyet, hoc hien
tao thiet » tai thiet, tay thiet, toan thiet
trang van » tran van, trang va, tang van
trong van » trong cac
trong san » trong cac, cong san, dong san
san toan » van toan, dan toan, manh toan
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) or (tao thiet)) tach - hanh ((trang van) OR (trong van)) dung trong san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thiet) OR (tao thiet)) tach - hanh ((trang van) OR (trong van)) dung trong san toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thiet) or (tao thiet)) tach - hanh ((trang van) OR (trong van)) dung trong san toan ban".
• Adding a wildcard symbol may retrieve word variants: ((hoc thiet) or (tao thiet)) tach - hanh ((trang van) OR (trong van)) dung trong san toan ban*.