Perhaps you should try some spelling variations:
hoan thanh » hoang thanh, ban thanh, van thanh
dong hoan » dong hoa, cong hoan, dang hoang
thanh cho » thanh pho, thanh cha, thanh chu
cach hoc » cach thuc, cach thoi, dich hoc
cuu dong » cuu cong, cuu tong, cuu long
hoi benh » hoc benh, hoa benh, hoi binh
nhan dan » phan dau, gian dan, nhan tai
tu cach » tu cac
cho hoc » co hoc, khoa hoc
ma hoi » mai hoi, xa hoi, ma hoa

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 dong hoan thanh cho hoc ma hoi benh ((nhan dan) or (phan tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach hoc tap, nghien cuu dong hoan thanh cho hoc ma hoi benh ((nhan dan) OR (phan tu)).
• Adding a wildcard symbol may retrieve word variants: tu cach hoc tap, nghien cuu dong hoan thanh cho hoc ma hoi benh ((nhan dan) or (phan tu))*.