Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
hanh trinh » canh tranh, hanh chinh
doi chieu » doc hieu, doi chi, ho chieu
cong tang » cong thang, cong tan, cong lang
tang luan » dung luan
vat mang » va mang, sat mang, vat ran
van nang » van quang, van ban, van dong
luan thu » luan thuc, tuan thu, lan thu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doi chieu tinh - hanh trinh ((vat mang) or (van nang)) cong tang luan thu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu tinh - hanh trinh ((vat mang) OR (van nang)) cong tang luan thu*.