Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
nganh khoa » nganh hoa, nganh khong, doanh khoa
hoa nganh » hoc nganh, khoi nganh, hoa doanh
sach hoc » cach hoc, sach hoi, mach hoc
cong hoa » dong hoa, dong hoc, hang hoa
khoa hoc » hoa hoc
nhan dan » gian dan, nhan tai
phan dau » phan tu, hang dau
te sach » toc sach
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: te sach hoc tap, nghien cua cong hoa nganh khoa hoc xa hoi va ((nhan dan) OR (phan dau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach hoc tap, nghien cua cong hoa nganh khoa hoc xa hoi va ((nhan dan) OR (phan dau))".
• Adding a wildcard symbol may retrieve word variants: te sach hoc tap, nghien cua cong hoa nganh khoa hoc xa hoi va ((nhan dan) OR (phan dau))*.