Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
sach nganh » sach ngan, sach tranh, cac nganh
trinh kxki » trinh khai, trinh khi, trinh khoi
kxki thuat » ki thuat, khoi thuat, kxy thuat
su sach » so sach, vu sach
y thuat » ky thuat, my thuat, kxy thuat
su canh » suc canh, su can, su anh
do hoc » do hoa, du hoc, mo 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: (( su sach nganh y thuat ((do hoc) OR (co hoc)) ) or ( su canh trinh kxki thuat toan khoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach nganh y thuat ((do hoc) OR (co hoc)) ) OR ( su canh trinh kxki thuat toan khoa )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( su sach nganh y thuat ((do hoc) OR (co hoc)) ) or ( su canh trinh kxki thuat toan khoa ))".
• Adding a wildcard symbol may retrieve word variants: (( su sach nganh y thuat ((do hoc) OR (co hoc)) ) or ( su canh trinh kxki thuat toan khoa ))*.