Perhaps you should try some spelling variations:
kki thuat » khoi thuat, ky thuat, mi thuat
ki thuat » ky thuat
sach kki » sach bai, sach kem, sach doi
su sach » so sach, vu sach
sach ki » sach kinh, sach bai, sach kem
thuat d » thuat do, thuat de, thuat di
tu sach » thu sach, te sach, tu cach
bo khi » co khi, bo chi, bo thi
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: (( su sach ki thuat d((o khi) or (bo khi)) ) or ( tu sach kki thuat ((o khi) or (bo khi)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach ki thuat d((o khi) OR (bo khi)) ) OR ( tu sach kki thuat ((o khi) OR (bo khi)) )).
• Adding a wildcard symbol may retrieve word variants: (( su sach ki thuat d((o khi) or (bo khi)) ) or ( tu sach kki thuat ((o khi) or (bo khi)) ))*.