Perhaps you should try some spelling variations:
hoc thuyet » hoc chuyen
thuyet xac » thuyet va, thuyet bai
thanh tung » thanh cong
tung cao » nung cao, truong cao, trung cap
cong dan » cong san, cong tan, cong dong
than cau » toan cau, phan cau, than cap
cao van » cac van, dao van, cao dang

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 xac - thanh tung cao van ((cong dan) or (huong dan)) than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thuyet xac - thanh tung cao van ((cong dan) OR (huong dan)) than cau.
• Adding a wildcard symbol may retrieve word variants: hoc thuyet xac - thanh tung cao van ((cong dan) or (huong dan)) than cau*.