Perhaps you should try some spelling variations:
khoa thong » hoa thong, thoai thong, pho thong
doanh khoa » toan khoa
truoc dang » thuoc dang, truoc bang, truoc cang
sach tren » sach tien, sach tranh
thu doanh » thu oanh, tri doanh, thu hoach
khoa khoa » hoa khoa, khuan khoa, khoa hoc
dang khoi » dung khoa, hang khoa
tren thu » tren thuc, tren thi, tien thu
gi truoc » gian truoc, _ truoc
so sach » so sanh, bo sach, co sach
sach gi » sach giao, sach bai, sach doi
khoi he » khoa he, khoi de, khong he

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sach tren thu doanh khoa khoa thong ) or ( so sach gi truoc dang khoi he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sach tren thu doanh khoa khoa thong ) OR ( so sach gi truoc dang khoi he thong )).
• Adding a wildcard symbol may retrieve word variants: (( so sach tren thu doanh khoa khoa thong ) or ( so sach gi truoc dang khoi he thong ))*.