Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
nganh khoa » nganh hoa, nganh khong, doanh khoa
hoc nganh » hoc nhanh
sach doi » sach hoi, sach moi, sach dao
cong hoc » dong hoc, cong hoa, cong coc
khoa hoc » hoa hoc
tu sach » thu sach, su sach, te sach
doi tap » doi tac, doi dap, doi tai
va phan » van phan, va phat, hoa phan
va phap » va phat, ban phap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach doi tap, nghien thu cong hoc nganh khoa hoc ma hoa ((va phan) OR (va phap)) dau~.
• Adding a wildcard symbol may retrieve word variants: tu sach doi tap, nghien thu cong hoc nganh khoa hoc ma hoa ((va phan) or (va phap)) dau*.