Perhaps you should try some spelling variations:
thuoc mach » thuong mach, thuoc ma, thuat mach
khoa thong » hoa thong, thoai thong, pho thong
thuoc sach » hoc sach, nuoc sach, thuat sach
tin thuoc » tin thuong, tin hoc, ban thuoc
tai thuoc » tri thuoc, bai thuoc, tac thuoc
hoc thong » hoc thuong, hoc trong, hoc hong
mach cua » manh cua, menh cua, hanh cua
cua khoa » chua khoa, sua khoa, qua khoa
sach tai » sach bai, sach tham, sach dao
cac tin » cac tinh, dac tinh, chuc tin
tu sach » thu sach, su sach, te sach
nha hoc » nha thuoc, khoa hoc, nha nuoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu cac tin thuoc mach cua khoa thong ) or ( tu sach tai thuoc sach nha hoc thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu cac tin thuoc mach cua khoa thong ) OR ( tu sach tai thuoc sach nha hoc thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu cac tin thuoc mach cua khoa thong ) or ( tu sach tai thuoc sach nha hoc thong ))*.