Perhaps you should try some spelling variations:
hoc thieu » toc thieu
nang quan » ban quan, nang suat
tang quan » tang luan, tong quan, thong quan
dung cong » dung trong
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
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 thieu) OR (hoc hien)) xanh - tinh ((nang quan) or (tang quan)) dung cong van toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thieu) OR (hoc hien)) xanh - tinh ((nang quan) OR (tang quan)) dung cong van toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thieu) OR (hoc hien)) xanh - tinh ((nang quan) or (tang quan)) dung cong van toan ban".
• Adding a wildcard symbol may retrieve word variants: ((hoc thieu) OR (hoc hien)) xanh - tinh ((nang quan) or (tang quan)) dung cong van toan ban*.