Perhaps you should try some spelling variations:
mki thuat » mi thuat, my thuat, ma thuat
sach mki » sach moi, bach mai, sach bai
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
sach ki » sach kinh, sach bai, sach kem
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 mki thuat co khi ) or ( vu sach ky thuat o khi ))) or ( tu sach ki thuat do thi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( vu sach mki thuat co khi ) OR ( vu sach ky thuat o khi ))) OR ( tu sach ki thuat do thi )).
• Adding a wildcard symbol may retrieve word variants: (((( vu sach mki thuat co khi ) or ( vu sach ky thuat o khi ))) or ( tu sach ki thuat do thi ))*.