Perhaps you should try some spelling variations:
thuoc mach » thuoc sach, thuong mach, thuoc ma
lam nguoi » dao nguoi, tay nguoi
cao nguoi » cho nguoi, dao nguoi, ca nguoi
doc sach » hoc sach, toc sach, nuoc sach
sach hoi » sach doi, cach thoi, hoach hoi
sach moi » sach doi, bach mai, sach bai
mach hoc » cach hoc, dich hoc, anh hoc
hoi lam » hoc lam, noi lam, loi lam
moi lam » moi la, noi lam, loi lam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (((( doc sach hoi lam nguoi ) OR ( doc sach moi lam nguoi ))) OR ( thuoc mach hoc cao nguoi ))~.
• Adding a wildcard symbol may retrieve word variants: (((( doc sach hoi lam nguoi ) or ( doc sach moi lam nguoi ))) or ( thuoc mach hoc cao nguoi ))*.