Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hoc thieu » toc thieu, hoc hien
dung cong » dung trong
tranh va » tranh van, trang va, trinh va
cong van » cong vang, cong san, song van
nhan tai » hang tai, van tai, toan tai
va dung » van dung, va duong, vat dung
tan tap » toan tap, tan tat, man tap
han tap » han tai, toan tap, nhan tao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - canh tranh va dung cong van ((tan tap) OR (((han tap) OR (nhan tai))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - canh tranh va dung cong van ((tan tap) or (((han tap) OR (nhan tai))))~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - canh tranh va dung cong van ((tan tap) or (((han tap) OR (nhan tai))))*.