Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
vinh toan » tinh toan, minh toan, vinh tran
hinh toan » tinh toan, thanh toan, trinh toan
trinh va » trinh van, trinh vat, trinh ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sach) or (hieu lang)) - hanh trinh va nhung cong ((vinh toan) OR (hinh toan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu lang)) - hanh trinh va nhung cong ((vinh toan) OR (hinh toan)) tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sach) or (hieu lang)) - hanh trinh va nhung cong ((vinh toan) OR (hinh toan)) tap".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (hieu lang)) - hanh trinh va nhung cong ((vinh toan) OR (hinh toan)) tap*.