Perhaps you should try some spelling variations:
nganh khoa » nganh hoa, nganh khong, doanh khoa
hoc nganh » hoc nhanh
sach doi » sach hoi, sach moi, sach dao
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
khoa hoc » hoa hoc
cac nhan » cac nha, cam nhan, dac nhan
tu sach » thu sach, su sach, te sach
doi tap » doi tac, doi dap, doi tai
ma voi » ba voi, da voi, ma moi

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 doi tap, nghien cuu cong hoc nganh khoa hoc ma voi ((cac nhan) OR (ca nhan)) tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach doi tap, nghien cuu cong hoc nganh khoa hoc ma voi ((cac nhan) OR (ca nhan)) tai".
• Adding a wildcard symbol may retrieve word variants: tu sach doi tap, nghien cuu cong hoc nganh khoa hoc ma voi ((cac nhan) OR (ca nhan)) tai*.