Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, nhung don
hoc chiet » hoc thiet, hoc nhiet, hoc hien
hang cong » dang cong, hang nong, bang cong
trinh ve » trinh he, trinh va, trinh vi
san toan » van toan, dan toan, manh toan
toan cau » toan cao, toan ban, toan tap

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 ve ((nhung cong) OR (hang cong)) san toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chiet tach - hanh trinh ve ((nhung cong) OR (hang cong)) san toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh trinh ve ((nhung cong) OR (hang cong)) san toan cau*.