Perhaps you should try some spelling variations:
hoc thuyet » hoc chuyen
hanh tranh » canh tranh, hanh trinh, hanh trang
hoc thiet » hoc thieu, hoc hien, toc thieu
tranh cua » doanh cua, manh cua
dung cong » dung trong
vang toan » van toan, quang toan, vang trang
dang toan » dang tran, dan toan, dung toan
cua dung » cua dang, cua dong, qua dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc thiet) or (hoc thuyet)) tach - hanh tranh cua dung cong ((vang toan) OR (dang toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thiet) OR (hoc thuyet)) tach - hanh tranh cua dung cong ((vang toan) OR (dang toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thiet) or (hoc thuyet)) tach - hanh tranh cua dung cong ((vang toan) OR (dang toan)) cau".
• Adding a wildcard symbol may retrieve word variants: ((hoc thiet) or (hoc thuyet)) tach - hanh tranh cua dung cong ((vang toan) OR (dang toan)) cau*.