Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
thanh kxy » than ky, thanh tay, thanh huy
nganh ki » nganh ky, nganh ke, nganh vi
ki thuat » ky thuat
thanh ky » hanh ky, than ky, thanh tay
tu sach » thu sach, su sach, te sach
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach nganh ki thuat o hoc ) OR ( tu canh ((thanh kxy) OR (thanh ky)) thuat toan khoa ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach nganh ki thuat o hoc ) or ( tu canh ((thanh kxy) OR (thanh ky)) thuat toan khoa ))~".
• Adding a wildcard symbol may retrieve word variants: (( tu sach nganh ki thuat o hoc ) or ( tu canh ((thanh kxy) OR (thanh ky)) thuat toan khoa ))*.