Perhaps you should try some spelling variations:
sach nganh » sach ngan, cac nganh, sach danh
sach tranh » canh tranh
canh trinh » canh tranh, hanh trinh, canh tinh
trinh kxy » trinh ky, trinh ly, trinh ke
kxy thuat » ky thuat, ki thuat, my thuat
va thuat » ky thuat, ki thuat, va thuc
thuat o » thuat do
tu canh » thu canh, tu chanh, tu can
o hoc » co hoc, mo hoc, so hoc
toan » tran

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 nganh) OR (sach tranh)) va thuat o hoc ) or ( tu canh trinh kxy thuat toan khoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu ((sach nganh) OR (sach tranh)) va thuat o hoc ) OR ( tu canh trinh kxy thuat toan khoa ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu ((sach nganh) OR (sach tranh)) va thuat o hoc ) or ( tu canh trinh kxy thuat toan khoa ))*".