Perhaps you should try some spelling variations:
van cham » van chat, van tham, va cham
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
cham dua » chay dua, cham giua, pham duc
cua tuc » cua duc, cua thuoc, luat tuc
dong ha » dong hoa, dong va, dong hoc
hanh va » hang va, hanh vi
dua ban » dia ban, cua ban, qua ban
sac ky » sai ky
cua tu » cua su, cua cu, cua te

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sac ky) OR (cac ky)) dong ha noi. hieu van cham dua ban hanh va ((cua tuc) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sac ky) OR (cac ky)) dong ha noi. hieu van cham dua ban hanh va ((cua tuc) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sac ky) OR (cac ky)) dong ha noi. hieu van cham dua ban hanh va ((cua tuc) or (cua tu))*".