Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
nganh xay » nganh mac, nganh y, nganh ma
can tranh » canh tranh, tan tran, van ranh
tranh ky » trinh ky, thanh ky, hanh ky
tu sach » thu sach, su sach, te sach
tu can » tu ban, tu cac, thu canh
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 xay ((thuat o) OR (thuat do)) hoc ) OR ( tu can tranh ky thuat toan khoa ))~.
• Adding a wildcard symbol may retrieve word variants: (( tu sach nganh xay ((thuat o) or (thuat do)) hoc ) or ( tu can tranh ky thuat toan khoa ))*.