Perhaps you should try some spelling variations:
kxy thuat » ky thuat, my thuat, ky thua
ki thuat » ky thuat
bach kxy » bac ky
tu sach » thu sach, su sach, te sach
sach ki » sach kinh, sach bai, sach kem
thuat o » thuat do
bo khi » co khi, bo chi
bo thi » bo thit, do thi, bo tai
o khi » 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 ki thuat ((bo khi) or (bo thi)) ) or ( vu bach kxy thuat o khi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach ki thuat ((bo khi) OR (bo thi)) ) OR ( vu bach kxy thuat o khi )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach ki thuat ((bo khi) or (bo thi)) ) or ( vu bach kxy thuat o khi ))*.