Perhaps you should try some spelling variations:
kki thuat » ki thuat, khoi thuat, ky thuat
sach dao » lanh dao
sach kki » sach bai, sach kem, sach doi
thuat do » thuat o
vu sach » vu bach, su sach, vu khach
phat co » phai co, nhat co, pha co
chat co » thuat co, chat cua, chat deo
phan co » phan bo, phan cong, phan cac
do khi » doi khi, do thi, 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: (( vu sach dao ((((phat co) OR (chat co))) or (phan 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) OR (chat co))) OR (phan co)) khi ) OR ( vu sach kki thuat do khi )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vu sach dao ((((phat co) OR (chat co))) or (phan co)) khi ) or ( vu sach kki thuat do khi ))".
• Adding a wildcard symbol may retrieve word variants: (( vu sach dao ((((phat co) OR (chat co))) or (phan co)) khi ) or ( vu sach kki thuat do khi ))*.