Perhaps you should try some spelling variations:
khong thanh » phong thanh, thong thanh, khong hanh
phan chung » phan cung, phan hung, phan thuong
chung hoc » trung hoc, dung hoc, hung hoa
mai khong » dai khong, ma khong, mai phuong
cach hoc » cach thuc, cach thoi, dich hoc
hoc phan » hoc dan, hoc pho
phan dau » phan tu
hang dau » hang va, hang tai
tu cach » tu cac
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
hoc mai » hoc ma, hoc dai, hoc bai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cach hoc tap, nghien cuu mon hoc phan chung hoc mai khong thanh ((phan dau) or (hang dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach hoc tap, nghien cuu mon hoc phan chung hoc mai khong thanh ((phan dau) OR (hang dau)).
• Adding a wildcard symbol may retrieve word variants: tu cach hoc tap, nghien cuu mon hoc phan chung hoc mai khong thanh ((phan dau) or (hang dau))*.