Perhaps you should try some spelling variations:
hoc khien » hoc hien, hoc nghien, hoc thieu
hanh sinh » hanh tinh, hanh dinh, hinh sinh
dung cong » dung trong
cong tan » cong tac, cong san, cong thanh
tan than » tan thanh, tan tran, ban than
than cap » khan cap, thanh lap, thanh cac
sinh va » sinh vat, tinh va, dinh van
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc khien) or (toc thieu)) tinh - hanh sinh va dung cong tan than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc khien) OR (toc thieu)) tinh - hanh sinh va dung cong tan than cap*.