Perhaps you should try some spelling variations:
trinh han » trinh quan
hang cong » dang cong, hang nong, bang cong
chi danh » chi dan, chi dinh, chi hanh
cong van » cong vang, cong san, song van
van tuan » van quan, van ban, anh tuan
tuan tai » toan tai, quan tai, tan tai
chi anh » chi hanh, thi anh, chi nhanh

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: doi ((chi danh) OR (chi anh)) - hanh ((trinh han) OR (tinh chat)) hang cong van tuan tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chi danh) OR (chi anh)) - hanh ((trinh han) or (tinh chat)) hang cong van tuan tai~".
• Adding a wildcard symbol may retrieve word variants: doi ((chi danh) OR (chi anh)) - hanh ((trinh han) or (tinh chat)) hang cong van tuan tai*.