Perhaps you should try some spelling variations:
thuat tach » thuat sach, thuat mach, thuat tac
tranh chua » tranh cua, trinh chuan, tranh chap
hoc thuat » hoc thuyet, hoc thuc, hoc chat
dong cang » dong bang, dong cung, dong nang
dong cong » duong cong, dung cong, dang cong
van cau » van dau, van hau, van chat
ban can » ban dan, ban hang, ban hanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thuat tach - canh tranh chua ((dong cang) or (dong cong)) thang ((van cau) or (ban can))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thuat tach - canh tranh chua ((dong cang) OR (dong cong)) thang ((van cau) OR (ban can)).
• Adding a wildcard symbol may retrieve word variants: hoc thuat tach - canh tranh chua ((dong cang) or (dong cong)) thang ((van cau) or (ban can))*.