Perhaps you should try some spelling variations:
kki thuat » ki thuat, khoi thuat, ky thuat
sach dao » lanh dao
dao phat » va phat
sach kki » sach bai, sach kem, sach doi
thuat do » thuat o
vu sach » vu bach, su sach, vu khach
phat co » chat co, phan co, phai co
do khi » doi khi, do thi, 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 dao phat co khi ) or ( vu sach kki thuat do khi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach dao phat co khi ) OR ( vu sach kki thuat do khi )).
• Adding a wildcard symbol may retrieve word variants: (( vu sach dao phat co khi ) or ( vu sach kki thuat do khi ))*.