Perhaps you should try some spelling variations:
vang thanh » van thanh, dang thanh, tang thanh
hoc chinh » hoan chinh, hoc sinh, hoc kinh
trinh ven » trinh van, trinh den, tinh ven
dung cong » dung trong
cong vang » cong lang, cong quang, cong ngang
thanh ban » thanh san, thanh van, thanh bac
trinh ve » trinh he, trinh va, trinh vi

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 chinh sach - hanh ((trinh ve) OR (trinh ven)) dung cong vang thanh ban~.
• Adding a wildcard symbol may retrieve word variants: hoc chinh sach - hanh ((trinh ve) or (trinh ven)) dung cong vang thanh ban*.