Perhaps you should try some spelling variations:
kki thuat » ki thuat, khoi thuat, mi thuat
toc sach » hoc sach, doc sach, thuoc sach
thuat co » thuat do, thuat o
thuat bo » thuat bao, thuat do, thuat o
tu cach » tu cac
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
bo khi » bo chi, bo thi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((tu cach) or (((te sach) OR (toc sach)))) kki thuat co khi ) or ( su sach ky thuat bo khi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu cach) OR (((te sach) OR (toc sach)))) kki thuat co khi ) OR ( su sach ky thuat bo khi )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu cach) or (((te sach) OR (toc sach)))) kki thuat co khi ) or ( su sach ky thuat bo khi ))".
• Adding a wildcard symbol may retrieve word variants: (( ((tu cach) or (((te sach) OR (toc sach)))) kki thuat co khi ) or ( su sach ky thuat bo khi ))*.