Perhaps you should try some spelling variations:
thuyet sach » thuyet mach, thuyet hach, thuyet xac
thuong cong » thong cong, thuong con, thuong dong
hoc thuyet » hoc chuyen
hanh trinh » canh tranh, hanh chinh
tran manh » tran minh, tran thanh, tran van
cong dan » cong san, cong tan, huong dan
than man » than ma, thanh san, than phan
luat » luan, xuat

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thuyet sach - hanh trinh luat thuong cong dan ((than man) or (tran manh))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thuyet sach - hanh trinh luat thuong cong dan ((than man) OR (tran manh)).
• Adding a wildcard symbol may retrieve word variants: hoc thuyet sach - hanh trinh luat thuong cong dan ((than man) or (tran manh))*.