Perhaps you should try some spelling variations:
hoc nganh » hoc nhanh
nganh hoa » thanh hoa, khanh hoa, danh hoa
gian dann » gian lang, gian dien, gian dac
sach hoc » cach hoc, sach hoi, mach hoc
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
gian dan » gian lang
tu sach » thu sach, su sach, te sach
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 sach hoc tap, nghien cuu cong hoc nganh hoa hoc ma hoi va ((gian dann) or (gian dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoc tap, nghien cuu cong hoc nganh hoa hoc ma hoi va ((gian dann) OR (gian dan)).
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien cuu cong hoc nganh hoa hoc ma hoi va ((gian dann) or (gian dan))*.