Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
dang phat » dang nhat, nang phat, hang phat
cong thuc » cong tac
thuc dan » thuc hanh, hoc dan, thuc vat
dan phan » doan phan, dan chan, van phan
phan lap » phan dau
phat va » chat va, pham va, phat vi
va cong » tai cong, cua cong

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc thieu) or (doi chieu)) lang - dang phat va cong thuc dan phan lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc thieu) OR (doi chieu)) lang - dang phat va cong thuc dan phan lap.
• Adding a wildcard symbol may retrieve word variants: ((toc thieu) or (doi chieu)) lang - dang phat va cong thuc dan phan lap*.