Perhaps you should try some spelling variations:
trinh chuan » trinh han, trinh quan, trinh luan
tranh chua » tranh cua, tranh chap, trinh chu
dung cong » dung trong
so thiet » soc thiet, hoc thiet, hoa thiet
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van 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 hien) or (so thiet)) tach - hanh ((tranh chua) OR (trinh chuan)) dung cong tan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc hien) OR (so thiet)) tach - hanh ((tranh chua) OR (trinh chuan)) dung cong tan toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc hien) or (so thiet)) tach - hanh ((tranh chua) OR (trinh chuan)) dung cong tan toan ban".
• Adding a wildcard symbol may retrieve word variants: ((hoc hien) or (so thiet)) tach - hanh ((tranh chua) OR (trinh chuan)) dung cong tan toan ban*.