Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hanh trinh » canh tranh, hanh chinh
cong quang » luong quang, thong quang, duong quang
hoc thieu » toc thieu, hoc hien
cong lang » cong vang, cong luong, cong ngang
trinh va » trinh van, trinh vat, trinh ve
toan cau » toan ban, toan tap, toan tai
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 va nhung ((cong lang) or (cong quang)) ((toan cau) OR (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh trinh va nhung ((cong lang) OR (cong quang)) ((toan cau) OR (toan cao)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - hanh trinh va nhung ((cong lang) or (cong quang)) ((toan cau) OR (toan cao))".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh trinh va nhung ((cong lang) or (cong quang)) ((toan cau) OR (toan cao))*.