Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
thanh tung » thanh cong
hoc thieu » toc thieu, hoc hien
dang cong » dung cong
nang quan » ban quan
tung va » trung va, tuong va, dung va
va dang » van dang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu xanh - thanh tung va dang cong ((nang quan) OR (nang suat)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - thanh tung va dang cong ((nang quan) OR (nang suat)) cau*".