Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
tien manh » tien anh, tien thanh, tieng anh
chinh cau » chinh chau, chinh ca, chinh can
hoc tien » hoc tieng, hoc hien, hoc vien
trinh va » trinh van, trinh vat, trinh ve
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
chan cau » phan cau, can cau, nhanh cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc tien manh - canh trinh va nhung ((cong dan) or (cong san)) ((chan cau) or (chinh cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc tien manh - canh trinh va nhung ((cong dan) OR (cong san)) ((chan cau) OR (chinh cau)).
• Adding a wildcard symbol may retrieve word variants: hoc tien manh - canh trinh va nhung ((cong dan) or (cong san)) ((chan cau) or (chinh cau))*.