Perhaps you should try some spelling variations:
sach ngan » sach ngon, sach nha, sach han
kxy thuat » ky thuat, ki thuat
my thuat » ky thuat, ki thuat, va thuat
thuat so » thuat do, thuat o, thuat co
tu sach » thu sach, su sach, te sach
ngan my » nhan my, nganh ma, nganh ky
tu canh » thu canh, tu chanh, tu can
ky thua » ky thuat, ky thu, ki thuat
so hoc » co hoc, mo hoc, so hoa
tranh » trinh, thanh, 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 ngan my thuat so hoc ) or ( tu canh tranh ((kxy thuat) OR (ky thua)) toan khoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach ngan my thuat so hoc ) OR ( tu canh tranh ((kxy thuat) OR (ky thua)) toan khoa ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach ngan my thuat so hoc ) or ( tu canh tranh ((kxy thuat) OR (ky thua)) toan khoa ))*".