Perhaps you should try some spelling variations:
thuyet hach » thuyet mach, thuyet xac, thuyet anh
thuyet cac » thuyet xac, thuyet va, thuyet bai
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » dung cong, thong cong, hang cong
tranh cua » doanh cua, manh cua
cua nhung » va nhung
van tuan » van quan, anh tuan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thuyet hach) OR (thuyet cac)) - hanh tranh cua nhung cong ((van tuan) OR (van ban)) cu~.
• Adding a wildcard symbol may retrieve word variants: hoc ((thuyet hach) or (thuyet cac)) - hanh tranh cua nhung cong ((van tuan) or (van ban)) cu*.