Perhaps you should try some spelling variations:
trinh han » trinh quan
trinh van » trinh quan, trinh toan, dinh van
dung cong » dung trong
doi chiu » doi chieu, doi chi, hoi chiu
cong ban » cong bang, cong san, cong tan
ban hang » ngan hang
hang ban » hang luan, hang va, hang tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chiu trach - hanh ((trinh han) or (trinh van)) dung cong ban hang ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiu trach - hanh ((trinh han) OR (trinh van)) dung cong ban hang ban.
• Adding a wildcard symbol may retrieve word variants: doi chiu trach - hanh ((trinh han) or (trinh van)) dung cong ban hang ban*.