Perhaps you should try some spelling variations:
sach dao » lanh dao
phan cac » nhan cach, phan dau, phan lap
ki thuat » ky thuat
thuat do » thuat o
vu sach » vu bach, su sach, vu khach
phat co » phan co, phai co, nhat co
chat co » thuat co, chat cua, chat deo
sach ki » sach kinh, sach bai, sach kem
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 cac)) khi ) or ( vu sach ki 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 cac)) khi ) OR ( vu sach ki thuat do khi )).
• Adding a wildcard symbol may retrieve word variants: (( vu sach dao ((((phat co) or (chat co))) or (phan cac)) khi ) or ( vu sach ki thuat do khi ))*.