Perhaps you should try some spelling variations:
kxy thuat » ki thuat, my thuat, ky thua
thuat do » thuat o
sach kxy » sach xa, sach kem, sac ky
tu sach » thu sach, te sach, tu cach
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
bao khi » bao chi, ban khi, bo khi
bao kha » bao khoa, bat kha, bao ha
do khi » doi khi, do thi, co khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach ky thuat do khi ) or ( su sach kxy thuat ((bao khi) or (bao kha)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach ky thuat do khi ) OR ( su sach kxy thuat ((bao khi) OR (bao kha)) )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach ky thuat do khi ) or ( su sach kxy thuat ((bao khi) or (bao kha)) ))*.