Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
chieu sang » chieu sach, chieu xanh, hieu lang
nhung cong » dung cong, thong cong, hang cong
hanh tang » hanh trang, anh tang, hanh mang
cong vang » cong lang, cong quang, cong ngang
toan cao » toan ban
toan tap » toan ban
tang va » trang va, tang van, thang va

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) or (chieu sang)) - hanh tang va nhung cong vang ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu sang)) - hanh tang va nhung cong vang ((toan cao) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (chieu sang)) - hanh tang va nhung cong vang ((toan cao) or (toan tap))*.