Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
hoc khanh » hoc nhanh, hoc thanh, hoc hanh
khanh hoa » thanh hoa, hang hoa
cach hoc » cach thuc, cach thoi, dich hoc
tung hoc » trung hoc, tuong hoc, dung hoc
hoi binh » hoa binh, hoi tinh, hoi sinh
nhan dan » gian dan, nhan tai
phan dau » phan tu, hang dau
tu cach » tu cac
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 huu tung hoc khanh hoa hoc ma hoi binh ((nhan dan) or (phan dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach hoc tap, nghien huu tung hoc khanh hoa hoc ma hoi binh ((nhan dan) OR (phan dau)).
• Adding a wildcard symbol may retrieve word variants: tu cach hoc tap, nghien huu tung hoc khanh hoa hoc ma hoi binh ((nhan dan) or (phan dau))*.