Perhaps you should try some spelling variations:
kxy thuat » ky thuat, ki thuat, ky thua
sach kxy » sach xa, sach kem, sac ky
my thuat » ky thuat, ki thuat, va thuat
vu sach » vu bach, su sach, vu khach
so sach » so sanh, bo sach, co sach
sach my » sach y, sach ty, sach mau
tu cach » tu cac
o khi » bo khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((( vu sach kxy thuat o khi ) or ( so sach my thuat co khi ))) or ( tu cach _ thuat do thi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( vu sach kxy thuat o khi ) OR ( so sach my thuat co khi ))) OR ( tu cach _ thuat do thi )).
• Adding a wildcard symbol may retrieve word variants: (((( vu sach kxy thuat o khi ) or ( so sach my thuat co khi ))) or ( tu cach _ thuat do thi ))*.