Perhaps you should try some spelling variations:
nganh khoa » nganh hoa, nganh khong, doanh khoa
hoc nganh » hoc nhanh
khoa hoc » hoa hoc
te sach » toc sach
sach do » sach dao, sach doi, sach de
cuu mon » cuu mo, cuu mot, cuu cong
mon hoc » toan hoc, dong hoc
ca gian » ca giang, ca giao, ca gia
va gian » va gianh, van gian, va giai
do dac » do duc, do dai, so dac
ma hoi » mai hoi, xa hoi, ma hoa

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach do dac, nghien cuu mon hoc nganh khoa hoc ma hoi ((ca gian) OR (va gian)) dan~".
• Adding a wildcard symbol may retrieve word variants: te sach do dac, nghien cuu mon hoc nganh khoa hoc ma hoi ((ca gian) OR (va gian)) dan*.