Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hoc thieu » toc thieu, hoc hien
hoc hieu » hoc hien, doc hieu, hoc dieu
trinh va » trinh van, trinh vat, trinh ve
trinh vi » trinh ve, trinh viet, trinh van
cong san » cong tac
san phan » san pham, van phan, sat phan
phan dau » phan tu, hang dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc hieu) OR (hoc thieu)) manh - canh ((trinh va) or (trinh vi)) thong cong san phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc hieu) OR (hoc thieu)) manh - canh ((trinh va) OR (trinh vi)) thong cong san phan dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc hieu) OR (hoc thieu)) manh - canh ((trinh va) or (trinh vi)) thong cong san phan dau".
• Adding a wildcard symbol may retrieve word variants: ((hoc hieu) OR (hoc thieu)) manh - canh ((trinh va) or (trinh vi)) thong cong san phan dau*.