Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
phan chong » phan cong, phan hong, phap chong
thanh toan » thanh hoa, thanh san, tinh toan
chong hoc » chung hoc, chong doc, thong hoc
van thanh » ban thanh, van tuan
sach hoc » sach hoi, mach hoc, sach duoc
cach hoc » cach thuc, cach thoi, dich hoc
cong hoc » dong hoc, cong hoa, cong coc
hoc phan » hoc dan, hoc pho
hoc xa » hoc ma
ha van » hoa van, nha van, va van
xa ha » xa hoa, xa hai, la ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach hoc) or (cach hoc)) tap, nghien thu cong hoc phan chong hoc xa ha van thanh toan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach hoc) OR (cach hoc)) tap, nghien thu cong hoc phan chong hoc xa ha van thanh toan.
• Adding a wildcard symbol may retrieve word variants: toc ((sach hoc) or (cach hoc)) tap, nghien thu cong hoc phan chong hoc xa ha van thanh toan*.