Perhaps you should try some spelling variations:
hoc nganh » hoc nhanh
nganh hoa » thanh hoa, khanh hoa, danh hoa
sach hoi » sach doi, sach moi, cach thoi
nhan tai » hang tai, van tai, toan tai
tu sach » thu sach, su sach, te sach
hoa cac » hoa chat, chon cac
cuu co » huu co, cua co, cuu mo
hoa ca » hoa cua, hoa cau, hoa xa

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