Perhaps you should try some spelling variations:
hien tach » thien hach, chiet tach, vien bach
hang cong » dang cong, hang nong, bang cong
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
cong van » cong vang, cong san, song van
phan tap » phan lap, han tap, phan tu
pha tap » pham tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien tach - hanh ((trinh va) or (trinh ve)) hang cong van ((phan tap) or (pha tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien tach - hanh ((trinh va) OR (trinh ve)) hang cong van ((phan tap) OR (pha tap)).
• Adding a wildcard symbol may retrieve word variants: hoc hien tach - hanh ((trinh va) or (trinh ve)) hang cong van ((phan tap) or (pha tap))*.