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
tren thuc » trien thuc, tron thuc, trinh thuc
tung tan » tung dan, hung tan, tang tan
cung tan » cung than, cong tan, cung ta
cong tac » cong ty
tren tau » tren may, tren dat, tren thi

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 - thanh ((tung tan) OR (cung tan)) dung cong tac ((tren tau) OR (tren thuc))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - thanh ((tung tan) OR (cung tan)) dung cong tac ((tren tau) or (tren thuc))~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - thanh ((tung tan) OR (cung tan)) dung cong tac ((tren tau) or (tren thuc))*.