Perhaps you should try some spelling variations:
thuong hang » thuong han, thuong hung, thuong lang
thieu sang » chieu sang, thieu khang, thieu quang
chieu sach » chinh sach, chiet tach, chieu sang
hanh trang » thanh trung, canh tranh, hanh trinh
trang va » tran van
luan ban » luan van, luan san, luan han
va luan » vay luan, van luan, va quan

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 sang) or (chieu sach)) - hanh trang va thuong hang va luan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (chieu sach)) - hanh trang va thuong hang va luan ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (chieu sach)) - hanh trang va thuong hang va luan ban*.