Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hanh tranh » canh tranh, hanh trang, lanh tranh
hanh trinh » canh tranh, hanh chinh
luan nhung » luan chung, luan hung, quan nhung
nhung cong » dung cong, thong cong, hang cong
chau tinh » cuu tinh, ha tinh, cua tinh
trinh hoa » trinh do, trinh han
hoa cau » hoa cac, hoa dau, hoa mau

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chieu sach) or (chau tinh)) - ((hanh tranh) OR (hanh trinh)) luan nhung cong trinh hoa cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chau tinh)) - ((hanh tranh) OR (hanh trinh)) luan nhung cong trinh hoa cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) or (chau tinh)) - ((hanh tranh) OR (hanh trinh)) luan nhung cong trinh hoa cau".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (chau tinh)) - ((hanh tranh) OR (hanh trinh)) luan nhung cong trinh hoa cau*.