Perhaps you should try some spelling variations:
thuat co » thuat do
so sach » so sanh, bo sach, co sach
y thuat » my thuat, kxy thuat, ki thuat
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach ty, sach kem
thuat o » thuat do
su xac » pu xac, su cac
xac ky » cac ky, sac ky, bac ky
o khi » bo khi

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( su xac ky thuat co khi ) OR ( so sach y thuat co khi ))) OR ( vu sach ky thuat o khi ))~".
• Adding a wildcard symbol may retrieve word variants: (((( su xac ky thuat co khi ) OR ( so sach y thuat co khi ))) OR ( vu sach ky thuat o khi ))*.