Perhaps you should try some spelling variations:
toc hieu » doc hieu, hoc thieu, thuc hieu
cong php » cong phu, chong phap, cong phan
php phan » phap phan, phe phan, phi phan
phan dam » phan dau, phan cam, phan dai
van chat » cao chat
chat cap » chat cam, chat cao, cao cap
dam van » dao van, nam van, pham van

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc hieu) or (toc thieu)) cach - thanh cong php phan dam van chat cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc hieu) OR (toc thieu)) cach - thanh cong php phan dam van chat cap*.