Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
sach hoc » cach hoc, sach hoi, mach hoc
sach doi » sach hoi, sach moi, sach dao
tung hoc » trung hoc, tuong hoc, dung hoc
dam nhan » dam phan, cam nhan, dac nhan
nhan tai » hang tai, van tai, toan tai
hoc anh » hoc nganh, hoc nhanh, ngoc anh
anh hoa » anh khoa, danh hoa, hanh hoa
hoi dam » hoi dap, hoi dan, hoi dat
hoc xa » hoc ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach hoc) or (sach doi)) tap, nghien huu tung hoc anh hoa hoc xa hoi dam nhan tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach hoc) OR (sach doi)) tap, nghien huu tung hoc anh hoa hoc xa hoi dam nhan tai.
• Adding a wildcard symbol may retrieve word variants: thuat ((sach hoc) or (sach doi)) tap, nghien huu tung hoc anh hoa hoc xa hoi dam nhan tai*.