Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
dung cong » dung trong
toc hieu » toc thieu, doc hieu, hoc thieu
cach ban » cac ban, cach ben, cach van
cach bao » cach nao, sach bao, cach giao
cua dung » cua dang, cua dong, qua dung
san phan » san pham, van phan, dan phan
sat phan » sat nhan, vat phan, xuat phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc hieu manh - ((cach ban) OR (cach bao)) cua dung cong ((san phan) or (sat phan)) lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc hieu manh - ((cach ban) OR (cach bao)) cua dung cong ((san phan) OR (sat phan)) lap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc hieu manh - ((cach ban) OR (cach bao)) cua dung cong ((san phan) or (sat phan)) lap".
• Adding a wildcard symbol may retrieve word variants: toc hieu manh - ((cach ban) OR (cach bao)) cua dung cong ((san phan) or (sat phan)) lap*.