Perhaps you should try some spelling variations:
tranh chuan » trinh chuan, tranh chua, tranh cua
thuc lanh » thuc hanh, thuat lanh, thuc thanh
dong cong » duong cong, dung cong, cong cong
dang cong » dung cong
thang ban » hang ban, tang ban, thanh ban
hoc thuc » hoc huu
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 thuc lanh - canh tranh chuan ((dong cong) or (dang cong)) thang ban can~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thuc lanh - canh tranh chuan ((dong cong) OR (dang cong)) thang ban can.
• Adding a wildcard symbol may retrieve word variants: hoc thuc lanh - canh tranh chuan ((dong cong) or (dang cong)) thang ban can*.