Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hoc thieu » toc thieu, hoc hien
trinh ven » trinh van, trinh den, tinh ven
dung cong » dung trong
trinh ve » trinh he, trinh va, trinh vi
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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 - hanh ((trinh ve) or (trinh ven)) ((dung cong) or (trong cong)) dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh ((trinh ve) OR (trinh ven)) ((dung cong) OR (trong cong)) dan toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh ((trinh ve) or (trinh ven)) ((dung cong) or (trong cong)) dan toan cau*.