Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trang » thanh trung, canh tranh, hanh trinh
cong luong » cong thuong, nang luong, cong dong
hoc chiet » hoc thiet, hoc nhiet, hoc hien
trang cua » tranh cua, tang cua, trung cua
tai toan » bai toan, tap toan, tam toan
tai tuan » tri tuan, ta tuan, tai 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 chiet tach - hanh trang cua cong luong ((tai toan) OR (tai tuan)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chiet tach - hanh trang cua cong luong ((tai toan) OR (tai tuan)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh trang cua cong luong ((tai toan) OR (tai tuan)) cao*.