Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cach hoc » cach thuc, cach thoi, dich hoc
cuu cong » cua cong, thu cong, cac cong
cong hoa » dong hoa, dong hoc, hang hoa
dan hoat » van hoa, dan hoc, danh hoa
hoat hoc » hoa hoc, hoat ho, khoa hoc
ban hang » ngan hang
vu cach » va cach, ve cach, vu bach
hoc mai » hoc ma, hoc dai, hoc bai
mai hoi » mai khoi, dai hoi, lai hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu cach hoc tap, nghien cuu cong hoa dan hoat hoc mai hoi ((van thanh) or (ban hang)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu cach hoc tap, nghien cuu cong hoa dan hoat hoc mai hoi ((van thanh) OR (ban hang)) van.
• Adding a wildcard symbol may retrieve word variants: vu cach hoc tap, nghien cuu cong hoa dan hoat hoc mai hoi ((van thanh) or (ban hang)) van*.