Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
phat tinh » phap tinh, phat minh, pha tinh
hoc phat » hoc phan, hoc pho
trang va » hang va
tran van » luan van
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc phat tinh - hanh ((trang va) or (tran van)) nhung cong san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc phat tinh - hanh ((trang va) OR (tran van)) nhung cong san toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc phat tinh - hanh ((trang va) or (tran van)) nhung cong san toan ban*.