Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
chieu xanh » chieu sach, chieu sang, chieu tinh
hanh tran » hanh trang, thanh tran, hanh tram
tuong dan » huong dan, xuong dan, truong dai
tung dan » dung dan, huong dan, trung dai
toan cau » toan cao, toan ban, toan tap
tran va » tran van, trang va, tranh 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 khang) or (chieu xanh)) - hanh tran va nhung ((tuong dan) or (tung dan)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu khang) OR (chieu xanh)) - hanh tran va nhung ((tuong dan) OR (tung dan)) toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu khang) or (chieu xanh)) - hanh tran va nhung ((tuong dan) or (tung dan)) toan cau*.