Perhaps you should try some spelling variations:
khoan phan » khoan phai, khoan thanh, hoa phan
khau thong » khau thuong, khap thong, khau tong
sach truc » cach thuc, sach tren, sach thu
phan tong » phan trong, phan cong, han tong
thuc toan » thuc trang, thuat toan, thuc thanh
khoa khau » khoa kham, khoa phau, khoa chau
truc tac » truc tai, truc bach, truc giac
sach tai » sach bai, sach tham, sach dao
tai thuc » thai thuc, tri thuc, dai thuc
te sach » toc sach
tac cac » thac cac, tai cac, tap cac
so sach » so sanh, bo sach, co sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te sach truc tac cac khoan phan tong ) or ( so sach tai thuc toan khoa khau thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach truc tac cac khoan phan tong ) OR ( so sach tai thuc toan khoa khau thong )).
• Adding a wildcard symbol may retrieve word variants: (( te sach truc tac cac khoan phan tong ) or ( so sach tai thuc toan khoa khau thong ))*.