Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
hoc chiet » hoc thiet, hoc nhiet, hoc hien
trinh vat » trinh van, trinh luat, sinh vat
vat nhung » va nhung, vap nhung, vai nhung
van thanh » ban thanh, van tuan
tan toan » tan tran, van toan, dan toan
tap toan » tap doan, tap quan, bai toan

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 trinh vat nhung cong ((((tan toan) or (van thanh))) or (tap toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - hanh trinh vat nhung cong ((((tan toan) OR (van thanh))) OR (tap toan)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh trinh vat nhung cong ((((tan toan) or (van thanh))) or (tap toan)) cau*.