Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
ki thuat » ky thuat
thuat bo » thuat bao, thuat do, thuat co
thuc bai » thuc tai, thuc ban, thuc thai
sach ki » sach kinh, sach bai, sach kem
thuat o » thuat do
tu sach » su sach, te sach, tu cach
y thuat » ky thuat, my thuat, kxy thuat
ve thuc » va thuc
bai khi » bai thi, ban khi, bai choi
bo khi » co khi, bo chi, bo thi
tu bac » tu ban, tu cac, tu bat
bac ve » bao ve, ban ve, bac le
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: (( thu sach ki thuat o khi ) or ((( tu sach y thuat bo khi ) or ( tu bac ve thuc bai khi ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu sach ki thuat o khi ) OR ((( tu sach y thuat bo khi ) OR ( tu bac ve thuc bai khi )))).
• Adding a wildcard symbol may retrieve word variants: (( thu sach ki thuat o khi ) or ((( tu sach y thuat bo khi ) or ( tu bac ve thuc bai khi ))))*.