Perhaps you should try some spelling variations:
nganh khoa » nganh hoa, nganh khong, doanh khoa
hoc nganh » hoc nhanh
toc sach » hoc sach, doc sach, thuoc sach
sach doi » sach hoi, sach moi, sach dao
khoa hoc » hoa hoc
gian dan » gian lang
nhan tai » hang tai, van tai, toan tai
doi tap » doi tac, doi dap, doi tai
cuu mot » cua mot, cuu mo, huu mot
mot hoc » mon hoc, mo hoc, mot goc
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: toc sach doi tap, nghien cuu mot hoc nganh khoa hoc ma hoi va ((gian dan) or (nhan tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach doi tap, nghien cuu mot hoc nganh khoa hoc ma hoi va ((gian dan) OR (nhan tai)).
• Adding a wildcard symbol may retrieve word variants: toc sach doi tap, nghien cuu mot hoc nganh khoa hoc ma hoi va ((gian dan) or (nhan tai))*.