Perhaps you should try some spelling variations:
khai thuong » khac thuong, hai thuong, khai chuong
thuoc cach » thuoc sach, thuc cach, truoc cach
tac thuoc » tao thuoc, truc thuoc, tac thuong
cach hoan » cac khoan, hach toan, sach han
hoan khai » hoang thai, khoan phai, hoang hai
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (hoc sach)) tac thuoc cach hoan khai thuong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) tac thuoc cach hoan khai thuong*.